U.S. patent application number 16/623624 was filed with the patent office on 2021-10-21 for flow cell, flow chamber, particle sorting apparatus, and particle sorting apparatus cartridge.
This patent application is currently assigned to Allied Flow Inc.. The applicant listed for this patent is Allied Flow Inc.. Invention is credited to Masahiko KANDA.
Application Number | 20210325290 16/623624 |
Document ID | / |
Family ID | 1000005723197 |
Filed Date | 2021-10-21 |
United States Patent
Application |
20210325290 |
Kind Code |
A1 |
KANDA; Masahiko |
October 21, 2021 |
FLOW CELL, FLOW CHAMBER, PARTICLE SORTING APPARATUS, AND PARTICLE
SORTING APPARATUS CARTRIDGE
Abstract
A flow cell includes a flow cell body portion. The flow cell
body portion is provided with a flow channel. A second end portion
of the flow cell is provided with a nozzle receiving portion. The
flow channel extends from the first end portion of the flow cell
body portion to the nozzle receiving portion. The nozzle receiving
portion is tapered toward the flow channel. The flow cell includes
a convex lens. The convex lens is attached on a portion of the
outer side surface of the flow cell body portion close to the
second end portion. The nozzle receiving portion is located at a
side close to the second end portion relative to an optical axis of
the convex lens.
Inventors: |
KANDA; Masahiko;
(Nishinomiya-shi, Hyogo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Allied Flow Inc. |
Nishinomiya-shi, Hyogo |
|
JP |
|
|
Assignee: |
Allied Flow Inc.
Nishinomiya-shi, Hyogo
JP
|
Family ID: |
1000005723197 |
Appl. No.: |
16/623624 |
Filed: |
August 23, 2018 |
PCT Filed: |
August 23, 2018 |
PCT NO: |
PCT/JP2018/031138 |
371 Date: |
December 17, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G01N 2015/1493 20130101;
G01N 2015/149 20130101; G01N 15/14 20130101 |
International
Class: |
G01N 15/14 20060101
G01N015/14 |
Claims
1. A flow cell comprising: a flow cell body portion, the flow cell
body portion having a first end portion, a second end portion
opposite to the first end portion, and an outer side surface
extending between the first end portion and the second end portion,
the flow cell body portion being provided with a flow channel, the
second end portion being provided with a nozzle receiving portion
communicating with the flow channel, the flow channel extending
from the first end portion to the nozzle receiving portion, the
nozzle receiving portion being tapered toward the flow channel; and
a convex lens attached on a portion of the outer side surface close
to the second end portion, wherein the nozzle receiving portion is
located at a side close to the second end portion relative to an
optical axis of the convex lens.
2. The flow cell according to claim 1, wherein a second angle is
more than or equal to a first angle, the first angle is given by
sin.sup.-1 (NA/n), where NA represents a numerical aperture of the
convex lens, and n represents a refractive index of the flow cell
body portion, and the second angle is an angle between a tapered
surface of the nozzle receiving portion and the optical axis in a
cross section defined by a first direction in which the flow
channel extends and a second direction in which the optical axis
extends.
3. The flow cell according to claim 1, wherein a second angle
between a tapered surface of the nozzle receiving portion and the
optical axis is more than or equal to 30.degree. in a cross section
defined by a first direction in which the flow channel extends and
a second direction in which the optical axis extends.
4. The flow cell according to claim 1, wherein a first distance
between the optical axis and an end portion of the flow channel
close to the nozzle receiving portion is less than or equal to 2.0
mm in a cross section defined by a first direction in which the
flow channel extends and a second direction in which the optical
axis extends.
5. The flow cell according to claim 1, wherein a first length of
the flow channel in a third direction is larger than a second
length of the flow channel in a second direction, the second
direction is a direction in which the optical axis of the convex
lens extends, and the third direction is perpendicular to the
second direction and a first direction in which the flow channel
extends.
6. The flow cell according to claim 1, further comprising a nozzle
including a third end portion having a tapered shape, wherein the
third end portion is received in the nozzle receiving portion, the
nozzle is provided with a nozzle channel communicating with the
flow channel, the nozzle channel has a cross sectional area smaller
than a cross sectional area of the flow channel, and the third end
portion is located at the side close to the second end portion
relative to the optical axis of the convex lens.
7. The flow cell according to claim 6, wherein a third angle is
equal to a second angle, the second angle is an angle between a
tapered surface of the nozzle receiving portion and the optical
axis in a cross section defined by a first direction in which the
flow channel extends and a second direction in which the optical
axis extends, and the third angle is an angle between the tapered
surface of the nozzle and the optical axis in the cross
section.
8. The flow cell according to claim 6, wherein a second distance
between the optical axis and an end portion of the nozzle channel
close to the flow channel is less than or equal to 2.0 mm in a
cross section defined by a first direction in which the flow
channel extends and a second direction in which the optical axis
extends.
9. The flow cell according to claim 6, wherein the nozzle is
detachably coupled to the flow cell body portion.
10. A flow chamber comprising: the flow cell recited in claim 1;
and a chamber attached to the flow cell, wherein a cavity of the
chamber communicates with the flow channel.
11. A particle sorting apparatus comprising: the flow chamber
recited in claim 10; and a detection optical system optically
coupled to the convex lens, wherein the detection optical system
includes a detection side lens optical system.
12. The particle sorting apparatus according to claim 11, further
comprising an alignment unit that aligns the flow channel with the
detection side lens optical system.
13. The particle sorting apparatus according to claim 12, further
comprising: an imaging unit optically coupled to the detection side
lens optical system; and a controller that controls the alignment
unit based on an output from the imaging unit.
14. The particle sorting apparatus according to claim 11, further
comprising: a housing provided with a first space to be sterilized;
and a transparent window member that is hermetically fitted in an
opening of the housing, wherein the flow cell and the chamber are
disposed in the first space, and the transparent window member
fluidly separates the detection side lens optical system from the
first space.
15. A particle sorting apparatus cartridge comprising: the flow
chamber recited in claim 10; a cartridge case that contains the
flow chamber; a transparent window member that faces the convex
lens and that is hermetically fitted in an opening of the cartridge
case; and a sample collection member that collects a droplet
ejected from the flow cell and that is attached to the cartridge
case.
Description
TECHNICAL FIELD
[0001] The present invention relates to a flow cell, a flow
chamber, a particle sorting apparatus, and a particle sorting
apparatus cartridge.
BACKGROUND ART
[0002] Due to progress in biotechnology, in various fields
including medical science and biology, a demand has been increased
for an apparatus that performs a process such as sorting or
analysis on a multiplicity of cell particles, which are exemplary
biological particles. As one example of such an apparatus, Japanese
Patent Laying-Open No. 2017-210278 (Patent Literature 1) discloses
a cell sorter. Specifically, the cell sorter disclosed in Patent
Literature 1 includes a flow cell, a transparent window member, and
an optical mechanism. In the flow cell, a sample liquid enclosed
with a sheath liquid flows. The transparent window member fluidly
isolates the optical mechanism from a space in which the flow cell
is disposed. The optical mechanism includes a light receiving unit
that detects light (fluorescence or scattered light) emitted from a
cell particle irradiated with laser light so as to detect
identification information of the cell particle. The fluorescence
or scattered light emitted from the cell particle passes through
the transparent window member, and enters the light receiving
unit.
CITATION LIST
Patent Literature
[0003] PTL 1: Japanese Patent Laying-Open No. 2017-210278
SUMMARY OF INVENTION
Technical Problem
[0004] In the cell sorter disclosed in Patent Literature 1,
however, an angle of the light that can be received by the light
receiving unit is limited. Hence, it is difficult to detect, with
high sensitivity, the identification information that characterizes
the cell particle. The present invention has been made in view of
the above-described problem, and has an object to provide a flow
cell, a flow chamber, a particle sorting apparatus, and a particle
sorting apparatus cartridge, by each of which identification
information that characterizes a particle can be detected with
improved sensitivity and the particle can be sorted with improved
sorting precision.
Solution to Problem
[0005] A flow cell according to the present invention includes a
flow cell body portion. The flow cell body portion has a first end
portion, a second end portion opposite to the first end portion,
and an outer side surface extending between the first end portion
and the second end portion. The flow cell body portion is provided
with a flow channel. The second end portion is provided with a
nozzle receiving portion communicating with the flow channel. The
flow channel extends from the first end portion to the nozzle
receiving portion. The nozzle receiving portion is tapered toward
the flow channel. The flow cell according to the present invention
includes a convex lens. The convex lens is attached on a portion of
the outer side surface of the flow cell body portion close to the
second end portion. The nozzle receiving portion is located at a
side close to the second end portion relative to an optical axis of
the convex lens.
[0006] A flow chamber according to the present invention includes:
the flow cell according to the present invention; and a chamber
attached to the flow cell. A cavity of the chamber communicates
with the flow channel.
[0007] A particle sorting apparatus according to the present
invention includes: the flow chamber according to the present
invention; and a detection optical system optically coupled to the
convex lens.
[0008] A particle sorting apparatus cartridge according to the
present invention includes: the flow chamber according to the
present invention; a transparent window member that faces the
convex lens; and a sample collection member that collects a droplet
ejected from the flow cell according to the present invention.
Advantageous Effects of Invention
[0009] With the flow cell, the flow chamber, the particle sorting
apparatus, and the particle sorting apparatus cartridge according
to the present invention, the identification information that
characterizes the particle can be detected with improved
sensitivity and the particle can be sorted with improved sorting
precision.
BRIEF DESCRIPTION OF DRAWINGS
[0010] FIG. 1 is a schematic cross sectional view of a particle
sorting apparatus according to a first embodiment.
[0011] FIG. 2 is a schematic partial enlarged cross sectional view
of the particle sorting apparatus according to the first
embodiment.
[0012] FIG. 3 is a schematic partial enlarged cross sectional view
of a flow cell according to the first embodiment.
[0013] FIG. 4 is a schematic partial enlarged cross sectional view
along a cross sectional line IV-IV shown in FIG. 3 in the flow cell
according to the first embodiment.
[0014] FIG. 5 is a schematic view showing an optical system of the
particle sorting apparatus according to the first embodiment.
[0015] FIG. 6 is a schematic partial enlarged view showing the
optical system of the particle sorting apparatus according to the
first embodiment.
[0016] FIG. 7 is a schematic partial enlarged view of a detection
optical system included in the particle sorting apparatus according
to the first embodiment.
[0017] FIG. 8 is a schematic partial enlarged view of the detection
optical system included in the particle sorting apparatus according
to the first embodiment.
[0018] FIG. 9 is a schematic partial enlarged view of a sorting
unit and a sample collection unit included in the particle sorting
apparatus according to the first embodiment.
[0019] FIG. 10 shows a flowchart of a method for sorting particles
according to the first embodiment.
[0020] FIG. 11 shows a flowchart of a step of aligning a flow
channel with a detection side lens optical system in the method for
sorting the particles according to the first embodiment.
[0021] FIG. 12 shows a flowchart of a step of sorting the particles
in the method for sorting the particles according to the first
embodiment.
[0022] FIG. 13 is a schematic cross sectional view of a particle
sorting apparatus according to a second embodiment (in which a
particle sorting apparatus cartridge is attached to a housing).
[0023] FIG. 14 is a schematic cross sectional view of the particle
sorting apparatus according to the second embodiment (in which the
particle sorting apparatus cartridge is detached from the
housing).
[0024] FIG. 15 is a schematic cross sectional view of a particle
sorting apparatus according to a third embodiment.
[0025] FIG. 16 is a schematic partial enlarged cross sectional view
of a flow cell according to the third embodiment.
[0026] FIG. 17 showing fluorescence data in a FITC channel
according to an Example 1.
[0027] FIG. 18 shows fluorescence data in a PE channel according to
an Example 2.
DESCRIPTION OF EMBODIMENTS
[0028] Hereinafter, embodiments of the present invention will be
described. It should be noted that the same configurations are
given the same reference numbers and will not be described
repeatedly.
First Embodiment
[0029] With reference to FIG. 1 to FIG. 9, the following describes
a flow cell 90, a flow chamber 40, and a particle sorting apparatus
30 according to a first embodiment. Particle sorting apparatus 30
sorts particles 145 (see FIG. 3) included in a sample liquid in the
following manner. Each of particles 145 included in the sample
liquid is irradiated with excitation light 111 (see FIG. 5 and FIG.
6). Based on identification information that is specific to
particle 145 and that is obtained by detecting light 117 (for
example, fluorescence or scattered light; see FIG. 3 to FIG. 5)
emitted from particle 145, charges are selectively applied to a
droplet 144 sent out from flow cell 90. A DC electric field is
formed on a path in which droplet 144 falls, thereby sorting out a
route of droplet 144. In this way, particles 145 included in
droplets 144 are sorted. Particles 145 are biological particles
such as cell particles, for example.
[0030] Particle sorting apparatus 30 mainly includes a flow chamber
40, a vibration electrode 60, a vibration element 74, a charge
supply unit 76, a transparent window member 121, and a detection
optical system 123, a sorting unit 150 (deflection plates 151, 152;
see FIG. 9), a collection unit 153 (sample collection members 154,
155, and a waste liquid collection member 156; see FIG. 9), an
alignment unit 80, a controller 170, and a housing 35. Flow chamber
40 includes a flow cell 90 and a chamber 41.
[0031] Housing 35 includes a separation wall 36. Separation wall 36
partitions an internal space of housing 35 into a first space 37
and a second space 38. First space 37 is fluidly isolated from
second space 38 by separation wall 36. First space 37 is fluidly
isolated from an external space by housing 35.
[0032] Flow chamber 40 (flow cell 90 and chamber 41) is contained
in first space 37. Sorting unit 150 (deflection plates 151, 152)
and collection unit 153 are contained in first space 37. In the
present embodiment, first space 37 is a closed space and the inside
of first space 37 is maintained to be in a hermetic state. The
inside of first space 37 can be sterilized by vapor of hydrogen
peroxide water or the like. Due to hitting or the like of droplets
144 against collection unit 153, aerosols are generated at a lower
portion of first space 37 in which sorting unit 150 (deflection
plates 151, 152) and collection unit 153 are located. The lower
portion of first space 37 is contaminated by the aerosols. By
sterilizing first space 37 by vapor of hydrogen peroxide water or
the like, the contamination of the lower portion of first space 37
by the aerosols can be removed securely. A sterile state is secured
in first space 37, and particles 145 included in the sample liquid
can be sorted under the sterile environment.
[0033] Vibration element 74, detection optical system 123,
alignment unit 80, and controller 170 are contained in second space
38.
[0034] A cavity 42 is provided inside chamber 41. Chamber 41 is
provided with a first inlet 43 and a second inlet 44 each
communicating with cavity 42. A first conduit 51 connected to a
sample liquid source unit 50 is inserted in first inlet 43. Sample
liquid source unit 50 stores a sample liquid including particles
145, and is disposed in first space 37. The sample liquid including
particles 145 is supplied from sample liquid source unit 50 to
cavity 42 of chamber 41 via first conduit 51.
[0035] A second conduit 53 connected to a sheath liquid source unit
52 is inserted in second inlet 44. Sheath liquid source unit 52
stores a sheath liquid, and is disposed external to housing 35
(first space 37). Second conduit 53 extends through housing 35.
Since sheath liquid source unit 52 is disposed external to housing
35 (first space 37), bacteria may be introduced into the sheath
liquid. In order to remove the bacteria, a filter 54 is provided in
second conduit 53. The sheath liquid is supplied from sheath liquid
source unit 52 to cavity 42 of chamber 41 via second conduit 53.
The sample liquid is supplied into cavity 42 of chamber 41 filled
with the sheath liquid. In this way, a sheath flow in which the
sample liquid is enclosed with the sheath liquid is formed in
cavity 42 of chamber 41.
[0036] Flow cell 90 is attached to chamber 41. Flow cell 90 may be
detachably coupled to chamber 41. Flow cell 90 includes a flow cell
body portion 91. Flow cell body portion 91 may be composed of a
transparent inorganic material such as quartz, or may be composed
of a transparent resin material.
[0037] Flow cell body portion 91 has a first end portion 92a, a
second end portion 92b opposite to first end portion 92a, and an
outer side surface 92s extending between first end portion 92a and
second end portion 92b. First end portion 92a of flow cell body
portion 91 is an end portion close to chamber 41. Second end
portion 92b of flow cell body portion 91 is an end portion far away
from chamber 41.
[0038] Flow cell body portion 91 is provided with a flow channel
95. Second end portion 92b of flow cell body portion 91 is provided
with a nozzle receiving portion 93 communicating with flow channel
95. Flow channel 95 extends from first end portion 92a to nozzle
receiving portion 93. Flow channel 95 communicates with cavity 42
of chamber 41. The sample liquid enclosed with the sheath liquid
flows from cavity 42 into flow channel 95 of flow cell 90. As shown
in FIG. 3, in flow channel 95, particles 145 included in the sample
liquid are arranged in one line along the center axis of flow
channel 95. Each of individual particles 145 is labeled with one or
more types of labeling materials (for example, fluorophores), for
example.
[0039] As shown in FIG. 4, in flow cell 90, a first length L.sub.1
of flow channel 95 in a third direction (y direction) is larger
than a second length L.sub.2 of flow channel 95 in a second
direction (x direction). The second direction (x direction) is a
direction in which an optical axis 120p of a convex lens 120
extends. The third direction (y direction) is perpendicular to the
second direction (x direction) and a first direction (z direction)
in which flow channel 95 extends. Therefore, an amount of light
vignetted by flow channel 95 in light 117 emitted from particle 145
is decreased.
[0040] Flow cell 90 further includes convex lens 120. As shown in
FIG. 3, convex lens 120 refracts light 117 emitted from particle
145 so as to reduce a spreading angle of light 117. Therefore,
convex lens 120 can guide, to detection optical system 123, light
117 emitted in a wider angle range. Convex lens 120 may be composed
of a transparent inorganic material such as quartz, or may be
composed of a transparent resin material. Convex lens 120 may be
composed of the same material as that of flow cell body portion 91,
or may be composed of a material different from that of flow cell
body portion 91.
[0041] Convex lens 120 is attached on a portion of outer side
surface 92s of flow cell body portion 91 close to second end
portion 92b (portion thereof far away from first end portion 92a).
Therefore, nozzle channel 106 can be close to optical axis 120p of
convex lens 120. A break-off point, at which a jet flow 140 is
broken off into a droplet 144, can be close to optical axis 120p of
convex lens 120, whereby identification information that
characterizes particle 145 can be detected at a position closer to
the break-off point. Particle 145 can be sorted with improved
sorting precision. It should be noted that in the present
specification, the portion close to second end portion 92b refers
to a portion of outer side surface 92s of flow cell body portion 91
at the second end portion 92b side relative to an intermediate line
between first end portion 92a and second end portion 92b.
[0042] In a cross section defined by the first direction (z
direction) in which flow channel 95 extends and the second
direction (x direction) in which optical axis 120p extends, a first
distance d.sub.1 (see FIG. 3) between optical axis 120p of convex
lens 120 and end portion 96 of flow channel 95 close to nozzle
receiving portion 93 is less than or equal to 2.0 mm, for example.
First distance d.sub.1 may be less than or equal to 1.5 mm, or may
be less than or equal to 1.0 mm. Nozzle channel 106 may be disposed
close to optical axis 120p of convex lens 120. The break-off point
at which jet flow 140 is broken off into droplet 144 can be close
to optical axis 120p of convex lens 120, whereby the identification
information that characterizes particle 145 can be detected at a
position closer to the break-off point. Particle 145 can be sorted
with improved sorting precision.
[0043] Convex lens 120 is directly attached to outer side surface
92s of flow cell body portion 91. Therefore, a distance between
convex lens 120 and the surface of flow channel 95 is decreased.
Convex lens 120 can guide, to detection optical system 123, light
117 emitted in a wider angle range. The identification information
that characterizes the particle can be detected with improved
sensitivity. In the present specification, such a fact that convex
lens 120 is directly attached to outer side surface 92s of flow
cell body portion 91 means that transparent window member 121 and
another optical member such as a lens are not disposed between
convex lens 120 and flow cell body portion 91. For example, convex
lens 120 is welded to outer side surface 92s of flow cell body
portion 91. Convex lens 120 may be formed in one piece with flow
cell body portion 91. Convex lens 120 may be adhered to outer side
surface 92s of flow cell body portion 91 using a transparent
adhesive agent, for example.
[0044] Convex lens 120 has a numerical aperture NA of more than or
equal to 0.80, for example. Numerical aperture NA of convex lens
120 may be more than or equal to 0.90, or may be more than or equal
to 1.00. Therefore, convex lens 120 can guide, to detection optical
system 123, light 117 emitted in a wider angle range. The
identification information that characterizes the particle can be
detected with improved sensitivity. It should be noted that in the
present specification, numerical aperture NA of convex lens 120 is
given by a product of a refractive index n of flow cell body
portion 91 and sin .theta.. A first angle .theta. is a maximum
angle between optical axis 120p of convex lens 120 and light 117
within flow cell body portion 91 to be guided to detection optical
system 123 by convex lens 120, in the cross section defined by the
first direction (z direction) in which flow channel 95 extends and
the second direction (x direction) in which optical axis 120p
extends. In other words, first angle .theta. is a maximum angle
between optical axis 120p of convex lens 120 and light 117 within
flow cell body portion 91 to be caught by convex lens 120, in the
cross section defined by the first direction (z direction) in which
flow channel 95 extends and the second direction (x direction) in
which optical axis 120p extends. First angle .theta. is given by
sin.sup.-1 (NA/n).
[0045] Convex lens 120 can have a long working distance WD (see
FIG. 7). Working distance WD is more than or equal to 10 mm, for
example. Therefore, even when transparent window member 121 is
disposed between convex lens 120 and detection optical system 123,
detection optical system 123 can be readily incorporated into
particle sorting apparatus 30 without transparent window member 121
mechanically interfering with detection optical system 123. It
should be noted that working distance WD is defined as a distance
on the optical axis of detection optical system 123 (optical axis
120p of convex lens 120) between the surface of flow channel 95 and
a surface, at the side close to flow cell 90, of a lens 124a
disposed closest to flow cell 90 in detection side lens optical
system 124.
[0046] Nozzle receiving portion 93 is located at the side close to
second end portion 92b relative to optical axis 120p of convex lens
120. Nozzle receiving portion 93 is tapered toward flow channel 95.
Therefore, an amount of light vignetted by tapered surface 94
(nozzle 100) of nozzle receiving portion 93 in light 117 emitted
from particle 145 is decreased. The identification information that
characterizes the particle can be detected with improved
sensitivity. An second angle .alpha. between tapered surface 94 of
nozzle receiving portion 93 and optical axis 120p is more than or
equal to 30.degree. in the cross section defined by the first
direction (z direction) in which flow channel 95 extends and the
second direction (x direction) in which optical axis 120p extends.
Second angle .alpha. may be more than or equal to 35.degree. or may
be more than or equal to 40.degree.. Second angle .alpha. may be
less than or equal to 70.degree. or may be less than or equal to
60.degree.. Specifically, flow cell 90 avoids light 117 from being
vignetted by tapered surface 94 (nozzle 100) of nozzle receiving
portion 93. For example, second angle .alpha. is more than or equal
to first angle .theta.. Hence, the identification information that
characterizes the particle can be detected with improved
sensitivity.
[0047] In a plan view in the second direction (x direction) in
which optical axis 120p of convex lens 120 extends, nozzle
receiving portion 93 overlaps with a portion of convex lens 120.
Therefore, nozzle channel 106 can be close to optical axis 120p of
convex lens 120. The break-off point at which jet flow 140 is
broken off into droplet 144 can be close to optical axis 120p of
convex lens 120, whereby the identification information that
characterizes particle 145 can be detected at a position closer to
the break-off point. Particle 145 can be sorted with improved
sorting precision.
[0048] As shown in FIG. 5, each of particles 145 arranged in one
line within flow channel 95 is irradiated with excitation light 111
from light source unit 110. Excitation light 111 includes light
having one or more wavelengths. In the present embodiment,
excitation light 111 includes light having a plurality of
wavelengths. As shown in FIG. 5 and FIG. 6, light source unit 110
includes laser units 110a, 110b, 110c, 110d, 110e, 110f, 110g, for
example. The wavelengths of beams of the laser light emitted from
laser units 110a, 110b, 110c, 110d, 110e, 110f, 110g are different
from one another. With excitation light 111 including the light
having the plurality of wavelengths, a plurality of pieces of
identification information of each particle 145 can be obtained at
one time. Particle 145 can be sorted efficiently.
[0049] As shown in FIG. 5 and FIG. 6, each of particles 145 flowing
in flow channel 95 is irradiated with excitation light 111 emitted
from light source unit 110 via an optical path conversion unit 112.
Optical path conversion unit 112 is a reflective mirror, for
example. Light 117 is emitted from particle 145. An incident
optical system including light source unit 110 and optical path
conversion unit 112 is fixed to housing 35.
[0050] Transparent window member 121 is hermetically fitted in an
opening 36b of separation wall 36, and is fixed to housing 35
(separation wall 36). Transparent window member 121 faces convex
lens 120. Transparent window member 121 is disposed between convex
lens 120 and detection optical system 123. Transparent window
member 121 fluidly separates detection optical system 123 from
first space 37. Accordingly, transparent window member 121 can
prevent detection optical system 123 from being contaminated by
aerosols generated in first space 37 due to hitting or the like of
droplets 144 against collection unit 153. Moreover, also when a
sterilization gas is supplied to first space 37 to sterilize first
space 37, detection optical system 123 is prevented from being
exposed to the sterilization gas. Accordingly, detection optical
system 123 is prevented from being damaged by the gas.
[0051] Detection optical system 123 is optically coupled to convex
lens 120. Light 117 emitted from particle 145 passes through convex
lens 120 and transparent window member 121, and enters detection
optical system 123. Detection optical system 123 may be fixed to
housing 35 (separation wall 36). Detection side lens optical system
124 is disposed at the side far away from convex lens 120 relative
to transparent window member 121. Detection optical system 123
includes detection side lens optical system 124. Detection side
lens optical system 124 is constituted of one or more lenses. As
shown in FIG. 7, in the present embodiment, detection side lens
optical system 124 is constituted of a plurality of lenses 124a,
124b, 124c, 124d, 124e, 124f, 124g, 124h, 124i, 124j, 124k.
Detection side lens optical system 124 images light 117 emitted
from particle 145, on an incident surface of an optical fiber array
130 with low chromatic aberration and low image aberration.
[0052] As shown in FIG. 1, FIG. 5, and FIG. 8, detection optical
system 123 further includes an optical fiber array 130 and a light
detection unit 132. Optical fiber array 130 is disposed between
detection side lens optical system 124 and light detection unit
132. A plurality of optical fibers 130f included in optical fiber
array 130 are disposed to correspond to the plurality of respective
laser units 110a, 110b, 110c, 110d, 110e, 110f, 110g. Optical fiber
array 130 transmits light 117 to light detection unit 132.
[0053] Light detection unit 132 includes a plurality of light
detectors 132f. The plurality of light detectors 132f are
photomultiplier tubes, for example. Detection optical system 123
may further include a wavelength division unit 131 (not shown).
Wavelength division unit 131 is disposed between optical fiber
array 130 and light detection unit 132 to divide light 117.
Wavelength division unit 131 includes a wavelength filter 131f and
a reflective mirror 131g.
[0054] Vibration electrode 60 extends from cavity 42 of chamber 41
to outside of chamber 41. Vibration electrode 60 includes a
vibration electrode portion 61 and an electrically conductive
portion 65. Electrically conductive portion 65 is inserted in an
opening 36a of separation wall 36. Electrically conductive portion
65 extends from second space 38 to first space 37 through opening
36a of separation wall 36. Specifically, electrically conductive
portion 65 is received in an insulation sleeve 70. Insulation
sleeve 70 is inserted in a hole of a sealing member 72. Sealing
member 72 is inserted in opening 36a of separation wall 36. Sealing
member 72 is an elastic seal such as a rubber seal, for example.
Sealing member 72 can be deformed elastically.
[0055] Flow chamber 40 includes vibration electrode portion 61.
Vibration electrode portion 61 is provided in chamber 41. Vibration
electrode portion 61 extends from cavity 42 of chamber 41 to the
outside of chamber 41. Vibration electrode portion 61 is provided
on a side surface of chamber 41 facing separation wall 36.
Vibration electrode portion 61 includes a first flange portion 62
and a first shank portion 63 extending from first flange portion
62. First flange portion 62 is provided on the side surface of
chamber 41 facing separation wall 36. First shank portion 63
extends from the side surface of chamber 41 to cavity 42 of chamber
41. An end surface 63a of first shank portion 63 is exposed to
cavity 42 of chamber 41. End surface 63a of first shank portion 63
is smoothly continuous to a surface 46 defined by cavity 42 of
chamber 41. Accordingly, the flow of the sheath liquid and the
sample liquid in cavity 42 of chamber 41 can be prevented from
being disturbed by end surface 63a of vibration electrode portion
61. Vibration electrode portion 61 includes a plurality of
protrusions 64. The plurality of protrusions 64 are provided at
first flange portion 62.
[0056] Electrically conductive portion 65 includes a second flange
portion 66 and a second shank portion 67 extending from second
flange portion 66. Second flange portion 66 faces first flange
portion 62. A plurality of recesses 68 are formed in electrically
conductive portion 65. The plurality of recesses 68 are formed in
second flange portion 66. The plurality of protrusions 64 are
fitted in the plurality of recesses 68, thereby electrically and
mechanically connecting vibration electrode portion 61 to
electrically conductive portion 65. Vibration electrode portion 61
can be stably positioned relative to electrically conductive
portion 65. The plurality of protrusions 64 and the plurality of
recesses 68 function as a positioning mechanism that defines a
position of vibration electrode portion 61 relative to electrically
conductive portion 65. As the positioning mechanism, the plurality
of recesses 68 may be formed in vibration electrode portion 61, and
the plurality of protrusions 64 may be formed in electrically
conductive portion 65, for example. In order to improve electric
connectivity between vibration electrode portion 61 and
electrically conductive portion 65, a metal layer (for example, a
nickel plating layer) may be formed at a connection portion between
vibration electrode portion 61 and electrically conductive portion
65.
[0057] As shown in FIG. 2, vibration electrode portion 61 is
detachably connected to electrically conductive portion 65. Hence,
flow chamber 40 (or chamber 41) can be attached to and detached
from housing 35 (separation wall 36). Used flow chamber 40 (or
chamber 41) may be exchanged with a flow chamber 40 (or chamber 41)
sterilized by applying radiation or heat thereto. Particles 145 can
be sorted in the sterile state at low cost.
[0058] Vibration element 74 is connected to vibration electrode 60.
Specifically, vibration element 74 is coupled to electrically
conductive portion 65. Vibration element 74 has a ring-like shape,
and electrically conductive portion 65 is inserted in the hole of
vibration element 74. Ultrasonic vibrations applied from vibration
element 74 to electrically conductive portion 65 are transmitted to
vibration electrode portion 61, and are further transmitted to the
sheath flow in cavity 42 of chamber 41 as well as jet flow 140.
Vibration electrode portion 61 transmits ultrasonic vibrations to
the sheath liquid and sample liquid in cavity 42 of chamber 41 as
well as jet flow 140. Vibration element 74 is a piezoelectric
element, for example.
[0059] Electrically conductive portion 65 is connected to charge
supply unit 76. Charge supply unit 76 supplies charges to
electrically conductive portion 65. The charges supplied to
electrically conductive portion 65 are supplied, via vibration
electrode portion 61, to the sheath flow in cavity 42 of chamber 41
and jet flow 140. Vibration electrode portion 61 supplies charges
to the sheath liquid and sample liquid in cavity 42 of chamber 41
as well as jet flow 140. The charges are supplied to droplet 144
including particle 145 so as to sort droplet 144 in sorting unit
150.
[0060] With vibration electrode 60, charges and ultrasonic
vibrations can be supplied to the sheath flow in cavity 42 of
chamber 41 and jet flow 140 without a connector of an electric
wiring being exposed to first space 37 in which chamber 41 is
disposed. Therefore, the connector of vibration electrode portion
61 can be prevented from being damaged by sterilization gas when
sterilizing first space 37 using the sterilization gas in order to
remove contamination resulting from aerosols of the sample liquid.
First space 37 can be readily sterilized using the sterilization
gas.
[0061] As shown in FIG. 1 and FIG. 3, flow cell 90 further includes
nozzle 100. Nozzle 100 may be composed of the same material as that
of flow cell body portion 91, or may be composed of a material
different from that of flow cell body portion 91. In the present
embodiment, flow cell body portion 91 is composed of quartz,
whereas nozzle 100 is composed of a metal material. With nozzle 100
being composed of the metal material, cost of nozzle 100 can be
decreased.
[0062] Nozzle 100 includes a third end portion 104 having a tapered
shape. Third end portion 104 of nozzle 100 is provided with a
nozzle channel 106 communicating with flow channel 95. Since third
end portion 104 has a tapered shape, an amount of light vignetted
by nozzle 100 in light 117 emitted from particle 145 is decreased.
Third end portion 104 is received in nozzle receiving portion 93.
Accordingly, nozzle channel 106 can be close to optical axis 120p
of convex lens 120. The break-off point at which jet flow 140 is
broken off into droplet 144 can be close to optical axis 120p of
convex lens 120, whereby the identification information that
characterizes particle 145 can be detected at a position closer to
the break-off point. Particle 145 can be sorted with improved
sorting precision. Third end portion 104 is located at the side
close to second end portion 92b relative to optical axis 120p of
convex lens 120.
[0063] A third angle .beta. is equal to second angle .alpha.. Third
angle .beta. is an angle between tapered surface 101 of nozzle 100
and optical axis 120p in the cross section defined by the first
direction (z direction) in which flow channel 95 extends and the
second direction (x direction) in which optical axis 120p extends.
Hence, tapered surface 101 of nozzle 100 makes surface contact with
tapered surface 94 of nozzle receiving portion 93. Nozzle 100 is
self-aligned with flow channel 95 to align nozzle channel 106 with
flow channel 95. Particle 145 can be sorted with improved sorting
precision.
[0064] Third angle .beta. is more than or equal to 30.degree. in
the cross section defined by the first direction (z direction) in
which flow channel 95 extends and the second direction (x
direction) in which optical axis 120p extends. Third angle .beta.
may be more than or equal to 35.degree. or may be more than or
equal to 40.degree.. Third angle .beta. may be less than or equal
to 70.degree. or may be less than or equal to 60.degree..
Specifically, nozzle 100 avoids light 117 from being vignetted by
nozzle 100. For example, third angle .beta. is more than or equal
to first angle .theta.. Therefore, the identification information
that characterizes the particle can be detected with improved
sensitivity.
[0065] Jet flow 140 in which the sample liquid is enclosed with the
sheath liquid is sent out from nozzle channel 106. Jet flow 140 is
sent out from nozzle channel 106 having a cross sectional area
smaller than that of flow channel 95, and vibrations generated in
vibration element 74 are transmitted to jet flow 140. Accordingly,
jet flow 140 is broken off into droplet 144 at the break-off point,
which is a lower end portion of j et flow 140.
[0066] In the cross section defined by the first direction (z
direction) in which flow channel 95 extends and the second
direction (x direction) in which optical axis 120p of convex lens
120 extends, a second distance d.sub.2 (see FIG. 3) between optical
axis 120p of convex lens 120 and an end portion 107 of nozzle
channel 106 close to flow channel 95 is determined by: the
numerical aperture (NA) of convex lens 120; the magnification of
the convex lens; and a center interval between two optical fibers
130f adjacent to each other in optical fiber array 130. Second
distance d.sub.2 is equal to first distance d.sub.1, or is larger
than first distance d.sub.1. Second distance d.sub.2 is less than
or equal to 2.0 mm, for example. Second distance d.sub.2 may be
less than or equal to 1.5 mm, or may be less than or equal to 1.0
mm. Nozzle channel 106 is disposed close to optical axis 120p of
convex lens 120. The break-off point at which jet flow 140 is
broken off into droplet 144 can be close to optical axis 120p of
convex lens 120, whereby the identification information that
characterizes particle 145 can be detected at a position closer to
the break-off point. Particle 145 can be sorted with improved
sorting precision.
[0067] Nozzle 100 may be provided with a tapered channel 108
communicating with flow channel 95 and nozzle channel 106. Tapered
channel 108 is provided at the side close to flow channel 95
relative to nozzle channel 106, and is connected to nozzle channel
106. Tapered channel 108 has a tapered shape toward nozzle channel
106. The cross-sectional area of tapered channel 108 is decreased
gradually toward nozzle channel 106. Accordingly, when the sheath
flow having flown out of flow channel 95 flows into nozzle channel
106, occurrence of a turbulent flow is suppressed in the sheath
flow. The position of the sample liquid in the sheath flow can be
suppressed from being displaced. Hence, particle 145 can be sorted
with improved sorting precision.
[0068] The end portion of tapered channel 108 close to flow channel
95 has the same cross sectional area as that of flow channel 95,
for example. The end portion of tapered channel 108 close to nozzle
channel 106 has the same cross sectional area as that of nozzle
channel 106, for example. The cross sectional area of nozzle
channel 106 is an area of nozzle channel 106 in a cross section
perpendicular to the direction (z direction) in which nozzle
channel 106 extends. The cross sectional area of tapered channel
108 is an area of tapered channel 108 in the cross section
perpendicular to the direction (z direction) in which tapered
channel 108 extends.
[0069] A nozzle cavity portion 105 communicating with nozzle
channel 106 is provided in nozzle 100. Nozzle cavity portion 105
has a larger cross sectional area than those of nozzle channel 106
and flow channel 95. The cross sectional area of nozzle cavity
portion 105 is an area of nozzle cavity portion 105 in the cross
section perpendicular to the direction (z direction) in which
nozzle cavity portion 105 extends. Jet flow 140 is sent out to the
outside of nozzle 100 through nozzle cavity portion 105. Nozzle 100
includes a flange portion 103 that is in contact with second end
portion 92b of flow cell body portion 91.
[0070] As shown in FIG. 9, sorting unit 150 includes a pair of
deflection plates 151, 152. Deflection plates 151, 152 have
basically the same configuration. With deflection plate 151 being
assumed as a representative example, the configuration of
deflection plate 151 will be described. An extension portion 151a
extending toward separation wall 36 is formed in deflection plate
151. A connector 160 is hermetically fitted in opening 36c of
separation wall 36. An opening 161 is formed in connector 160.
Extension portion 151a is inserted in opening 161. Deflection plate
151 may be attachable to and detachable from connector 160. An O
ring 162 serving as a sealing member is disposed between extension
portion 151a and the inner wall of opening 161. Extension portion
151a is connected to controller 170 via a wiring.
[0071] By applying voltage between deflection plates 151, 152, an
electric field is formed between deflection plates 151, 152.
Charges corresponding to the identification information of each
particle 145 detected by light detection unit 132 is supplied from
vibration electrode portion 61 to droplet 144 via the sheath flow
in cavity 42 of chamber 41 and jet flow 140. Droplet 144 is fed
with force by the electric field between deflection plates 151,
152. Depending on the charges supplied to droplet 144, a falling
direction of droplet 144 is changed.
[0072] As shown in FIG. 9, collection unit 153 includes the
plurality of sample collection members 154, 155 and waste liquid
collection member 156. Sample collection members 154, 155 are
attached to housing 35 (separation wall 36). Sample collection
members 154, 155 may be detachably attached to housing 35
(separation wall 36). Droplets 144 having falling directions
changed in sorting unit 150 are caught in corresponding sample
collection members 154, 155. In this way, particle 145 included in
each droplet 144 can be sorted in accordance with the
identification information thereof. An unnecessary droplet 144 is
caught in waste liquid collection member 156.
[0073] With reference to FIG. 1, alignment unit 80 aligns flow
channel 95 with detection side lens optical system 124. Alignment
unit 80 is, for example, a triple-axis moving mechanism, and moves
flow channel 95 in the first direction (z direction), the second
direction (x direction), and the third direction (y direction).
Alignment unit 80 is attached to separation wall 36 via a fixing
portion 79. Alignment unit 80 is coupled to vibration electrode 60
(electrically conductive portion 65) via a movable member 78.
Vibration electrode 60 (electrically conductive portion 65) can be
moved in a range (for example, an elastic deformation amount of
.+-.1.0 mm) in which sealing member 72 can be deformed elastically.
Alignment unit 80 moves movable member 78 and vibration electrode
60 to move flow chamber 40 (chamber 41).
[0074] As shown in FIG. 1 and FIG. 5, particle sorting apparatus 30
further includes an imaging unit 137 and a reflective member 134.
Reflective member 134 is a half mirror, for example. Reflective
member 134 is disposed between detection side lens optical system
124 and optical fiber array 130. Reflective member 134 reflects at
least part of light 117 emitted from particle 145, toward imaging
unit 137. An image of flow channel 95 and an image of light 117
emitted from particle 145 are obtained by imaging unit 137. Data of
these images obtained by imaging unit 137 is output to controller
170.
[0075] Based on the data of the images output from imaging unit
137, controller 170 controls alignment unit 80. For example,
controller 170 controls alignment unit 80 to attain maximum
intensity of light 117 emitted from particle 145. Alignment unit 80
moves flow chamber 40 using movable member 78 and vibration
electrode 60. In this way, flow channel 95 is aligned with the
incident optical system and detection optical system 123 (detection
side lens optical system 124). Whenever flow chamber 40 is attached
to particle sorting apparatus 30, flow channel 95 is aligned with
the optical axis of excitation light 111 and the optical axis of
detection optical system 123 (optical axis 120p of convex lens 120)
using alignment unit 80. Accordingly, high particle detection
sensitivity of particle sorting apparatus 30 can be maintained.
[0076] Particle sorting apparatus 30 may further include a
reflective member driving unit 135 that moves reflective member
134. When aligning flow chamber 40 with detection optical system
123, reflective member driving unit 135 positions reflective member
134 on the optical axis of detection optical system 123 (optical
axis 120p of convex lens 120). When detecting the specific
identification information that characterizes each particle 145 by
detecting light 117 emitted from particle 145, reflective member
driving unit 135 retreats reflective member 134 from the optical
axis of detection optical system 123 (optical axis 120p of convex
lens 120). Accordingly, when detecting the specific identification
information that characterizes each particle 145 by detecting light
117 emitted from particle 145, part of light 117 emitted from
particle 145 is prevented from failing to reach light detection
unit 132 due to reflective member 134. The particle detection
sensitivity of particle sorting apparatus 30 is prevented from
being decreased.
[0077] Controller 170 is electrically connected to vibration
element 74, charge supply unit 76, alignment unit 80, light
detection unit 132, reflective member driving unit 135, imaging
unit 137, and deflection plates 151, 152. Controller 170 controls
vibration element 74 to control on/off, frequency, and the like of
ultrasonic vibrations to be applied from vibration element 74 to
vibration electrode 60. Controller 170 controls alignment unit 80
to control movement direction and movement distance of flow chamber
40.
[0078] Controller 170 controls charge supply unit 76. Specifically,
controller 170 receives the identification information of each
particle 145 detected by light detection unit 132, and controls, in
accordance with this identification information, polarity and
amount of charges to be supplied from charge supply unit 76 to
vibration electrode 60. Controller 170 controls reflective member
driving unit 135. Controller 170 receives the data of the image of
flow channel 95 and the data of the image of light 117 emitted from
particle 145, both of which are obtained by imaging unit 137, and
controls alignment unit 80 based on the data of these images.
Controller 170 controls the electric field applied between
deflection plates 151, 152.
[0079] With reference to FIG. 10 to FIG. 12, a method for sorting
particles using particle sorting apparatus 30 will be
described.
[0080] With reference to FIG. 10, the method for sorting the
particles according to the present embodiment includes attaching
flow chamber 40 to housing 35 (separation wall 36) (S10).
Specifically, flow chamber 40, first conduit 51, and second conduit
53 are sterilized by applying radiation or heat to flow chamber 40,
first conduit 51, and second conduit 53. First conduit 51 is
inserted into first inlet 43 of chamber 41, and second conduit 53
is inserted into second inlet 44 of chamber 41. Flow chamber 40 is
attached to separation wall 36 of housing 35. Specifically,
vibration electrode portion 61 is attached to electrically
conductive portion 65 fixed to housing 35 (separation wall 36). The
plurality of protrusions 64 of vibration electrode portion 61 are
fitted in the plurality of recesses 68 of electrically conductive
portion 65. Vibration electrode portion 61 is positioned relative
to electrically conductive portion 65.
[0081] With reference to FIG. 10, the method for sorting the
particles according to the present embodiment includes aligning
flow channel 95 with detection side lens optical system 124 (S20).
That is, flow chamber 40 is aligned with detection optical system
123 using alignment unit 80.
[0082] With reference to FIG. 11, reflective member driving unit
135 is used to position reflective member 134 on the optical axis
of detection optical system 123 (optical axis 120p of convex lens
120) (S21). The sample liquid and the sheath liquid are supplied to
cavity 42 of chamber 41 (S22). Specifically, the sheath liquid is
supplied from sheath liquid source unit 52 to cavity 42 of chamber
41 through second conduit 53. Cavity 42 of chamber 41 is filled
with the sheath liquid. Then, the sample liquid is supplied from
sample liquid source unit 50 to cavity 42 of chamber 41 through
first conduit 51. In cavity 42 of chamber 41, the sheath flow in
which the sample liquid is enclosed with the sheath liquid is
formed. The sheath flow flows from cavity 42 of chamber 41 into
flow channel 95 of flow cell 90. In flow channel 95, particles 145
included in the sample liquid are arranged in one line along the
center axis of flow channel 95. Each of individual particles 145 is
labeled with one or more types of label materials (for example,
fluorophores), for example.
[0083] Each of individual particles 145 arranged in one line within
flow channel 95 is irradiated with excitation light 111 using light
source unit 110 (S23). Light 117 is emitted from particle 145.
Light 117 emitted from particle 145 enters reflective member 134
via convex lens 120, transparent window member 121, and detection
side lens optical system 124. At least part of light 117 is
reflected by reflective member 134, and enters imaging unit 137.
Imaging unit 137 is used to obtain the image of flow channel 95 and
the image of light 117 emitted from particle 145 (S24). Imaging
unit 137 outputs the data of these images to controller 170.
[0084] Based on the data of the images obtained by imaging unit
137, flow chamber 40 is aligned with detection optical system 123
(S25). Based on the data of the images output from imaging unit
137, controller 170 controls alignment unit 80. The incident
optical system including light source unit 110 and optical path
conversion unit 112 and detection optical system 123 are fixed to
housing 35 (separation wall 36). Controller 170 controls alignment
unit 80 to attain maximum intensity of light 117 emitted from
particle 145. Alignment unit 80 moves flow chamber 40 using movable
member 78 and vibration electrode 60. In this way, flow channel 95
is aligned with the incident optical system and detection optical
system 123 (detection side lens optical system 124). Then,
reflective member driving unit 135 is used to retreat reflective
member 134 from the optical axis of detection optical system 123
(optical axis 120p of convex lens 120) (S26).
[0085] With reference to FIG. 10, the method for sorting particles
according to the present embodiment includes sorting particles 145
(S30). With reference to FIG. 12, specifically, the sample liquid
and the sheath liquid are supplied to cavity 42 of chamber 41
(S31). In cavity 42 of chamber 41, the sheath flow in which the
sample liquid is enclosed with the sheath liquid is formed. The
sheath flow flows from cavity 42 of chamber 41 into flow channel 95
of flow cell 90. In flow channel 95, individual particles 145
included in the sample liquid are arranged in one line along the
center axis of flow channel 95. Each of individual particles 145 is
labeled with one or more types of label materials (for example,
fluorophores), for example.
[0086] Each of individual particles 145 arranged in one line within
flow channel 95 is irradiated with excitation light 111 using light
source unit 110 (S32). Light 117 is emitted from particle 145.
Light 117 emitted from particle 145 enters optical fiber array 130
via convex lens 120, transparent window member 121, and detection
side lens optical system 124. Light 117 emitted from particle 145
is imaged on an incident surface of an optical fiber array 130.
Optical fiber array 130 transmits light 117 emitted from particle
145, to light detection unit 132. Light 117 emitted from particle
145 is detected by light detection unit 132, thereby detecting the
identification information that characterizes particle 145 (S33).
Light 117 emitted from particle 145 may be divided by wavelength
division unit 131 before being detected by light detection unit
132.
[0087] Charges corresponding to the identification information of
particle 145 detected by light detection unit 132 are supplied to
droplet 144 (S34). Specifically, the charges corresponding to the
identification information of particle 145 detected by light
detection unit 132 are supplied from vibration electrode portion 61
to droplet 144 via the sheath flow in cavity 42 of chamber 41 and
jet flow 140. No charges are supplied to an unnecessary droplet
144.
[0088] Particle 145 is sorted in accordance with the identification
information of particle 145 (S35). Specifically, voltage is applied
between deflection plates 151, 152 to form an electric field
between deflection plates 151, 152. Droplet 144 is fed with force
by this electric field. Depending on the charges supplied to
droplet 144, a falling direction of droplet 144 is changed.
Droplets 144 having falling directions changed are caught in
corresponding sample collection members 154, 155. In this way,
particle 145 included in each droplet 144 can be sorted in
accordance with the identification information of particle 145. An
unnecessary droplet 144 is caught in waste liquid collection member
156.
[0089] The following describes effects of flow cell 90, flow
chamber 40, and particle sorting apparatus 30 according to the
present embodiment.
[0090] A flow cell 90 according to the present embodiment includes
a flow cell body portion 91. Flow cell body portion 91 has a first
end portion 92a, a second end portion 92b opposite to first end
portion 92a, and an outer side surface 92s extending between first
end portion 92a and second end portion 92b. Flow cell body portion
91 is provided with a flow channel 95. Second end portion 92b is
provided with a nozzle receiving portion 93 communicating with flow
channel 95. Flow channel 95 extends from first end portion 92a to
nozzle receiving portion 93. Nozzle receiving portion 93 is tapered
toward flow channel 95. Flow cell 90 further includes a convex lens
120. Convex lens 120 is attached on a portion of outer side surface
92s of flow cell body portion 91 close to second end portion 92b.
Nozzle receiving portion 93 is located at a side close to second
end portion 92b relative to an optical axis 120p of convex lens
120.
[0091] Light 117 emitted from particle 145 is refracted by convex
lens 120 attached to outer side surface 92s of flow cell body
portion 91. Convex lens 120 decreases the spreading angle of light
117. Convex lens 120 can guide, to detection optical system 123,
light 117 emitted in a wider angle range. Moreover, since nozzle
receiving portion 93 is tapered toward flow channel 95, an amount
of light vignetted by nozzle 100 in light 117 emitted from particle
145 is decreased. Flow cell 90 enables that the identification
information that characterizes each particle 145 flowing in flow
channel 95 is detected with a larger amount of light 117.
Accordingly, flow cell 90 enables that the identification
information that characterizes each particle 145 is detected with
improved sensitivity.
[0092] Convex lens 120 is attached to the portion of outer side
surface 92s of flow cell body portion 91 close to second end
portion 92b. Accordingly, nozzle channel 106 can be close to
optical axis 120p of convex lens 120. The break-off point at which
jet flow 140 is broken off into droplet 144 can be close to optical
axis 120p of convex lens 120, whereby the identification
information that characterizes particle 145 can be detected at a
position closer to the break-off point. Flow cell 90 enables that
particle 145 is sorted with improved sorting precision.
[0093] In flow cell 90 according to the present embodiment, a
second angle .alpha. is more than or equal to a first angle
.theta.. First angle .theta. is given by sin.sup.-1 (NA/n). NA
represents a numerical aperture of convex lens 120, and n
represents a refractive index of flow cell body portion 91. Second
angle .alpha. is an angle between a tapered surface 94 of nozzle
receiving portion 93 and optical axis 120p of convex lens 120 in a
cross section defined by a first direction (z direction) in which
flow channel 95 extends and a second direction (x direction) in
which optical axis 120p of convex lens 120 extends. Accordingly,
light 117 in flow cell body portion 91 to be guided to detection
optical system 123 by convex lens 120 can be prevented from being
vignetted by tapered surface 94 (nozzle 100) of nozzle receiving
portion 93. Flow cell 90 enables that the identification
information that characterizes particle 145 is detected with
improved sensitivity.
[0094] In flow cell 90 according to the present embodiment, a
second angle between a tapered surface 94 of nozzle receiving
portion 93 and optical axis 120p of convex lens 120 is more than or
equal to 30.degree. in a cross section defined by a first direction
(z direction) in which flow channel 95 extends and a second
direction (x direction) in which optical axis 120p of convex lens
120 extends. An amount of light vignetted by tapered surface 94
(nozzle 100) of nozzle receiving portion 93 in light 117 emitted
from particle 145 is decreased. Flow cell 90 enables that the
identification information that characterizes particle 145 is
detected with improved sensitivity.
[0095] In flow cell 90 according to the present embodiment, a first
distance d.sub.1 between optical axis 120p of convex lens 120 and
an end portion 96 of flow channel 95 close to nozzle receiving
portion 93 is less than or equal to 2.0 mm in a cross section
defined by a first direction (z direction) in which flow channel 95
extends and a second direction (x direction) in which optical axis
120p of convex lens 120 extends. Hence, nozzle channel 106 may be
disposed close to optical axis 120p of convex lens 120. The
break-off point at which jet flow 140 is broken off into droplet
144 can be close to optical axis 120p of convex lens 120, whereby
the identification information that characterizes particle 145 can
be detected at a position closer to the break-off point. Particle
145 can be sorted with improved sorting precision.
[0096] In flow cell 90 according to the present embodiment, a first
length L.sub.1 of flow channel 95 in a third direction (y
direction) is larger than a second length L.sub.2 of flow channel
95 in a second direction (x direction). The second direction (x
direction) is a direction in which optical axis 120p of convex lens
120 extends. The third direction (y direction) is perpendicular to
the second direction (x direction) and a first direction (z
direction) in which flow channel 95 extends. Therefore, an amount
of light vignetted by the surface of flow channel 95 in light 117
emitted from particle 145 is decreased. Flow cell 90 enables that
the identification information that characterizes particle 145 is
detected with improved sensitivity.
[0097] Flow cell 90 according to the present embodiment further
includes a nozzle 100. Nozzle 100 includes a third end portion 104
having a tapered shape. Third end portion 104 is received in nozzle
receiving portion 93. Nozzle 100 is provided with a nozzle channel
106 communicating with flow channel 95. Nozzle channel 106 has a
cross sectional area smaller than a cross sectional area of flow
channel 95. Third end portion 104 is located at the side close to
second end portion 92b relative to optical axis 120p of convex lens
120.
[0098] Third end portion 104 has a tapered shape. Third end portion
104 is located at the side close to second end portion 92b relative
to optical axis 120p of convex lens 120. Therefore, an amount of
light vignetted by nozzle 100 in light 117 emitted from particle
145 is decreased. Flow cell 90 enables that the identification
information that characterizes particle 145 is detected with
improved sensitivity.
[0099] Further, third end portion 104 is received in nozzle
receiving portion 93. Accordingly, nozzle channel 106 can be close
to optical axis 120p of convex lens 120. The break-off point at
which jet flow 140 is broken off into droplet 144 can be close to
optical axis 120p of convex lens 120, whereby the identification
information that characterizes particle 145 can be detected at a
position closer to the break-off point. Flow cell 90 enables that
particle 145 is sorted with improved sorting precision.
[0100] In flow cell 90 according to the present embodiment, a third
angle is equal to a second angle .alpha.. Second angle .alpha. is
an angle between a tapered surface 94 of nozzle receiving portion
93 and optical axis 120p of convex lens 120 in a cross section
defined by a first direction (z direction) in which flow channel 95
extends and a second direction (x direction) in which optical axis
120p of convex lens 120 extends. Third angle .beta. is an angle
between tapered surface 101 of nozzle 100 and optical axis 120p of
convex lens 120 in the cross section. Hence, tapered surface 101 of
nozzle 100 makes surface contact with tapered surface 94 of nozzle
receiving portion 93. Nozzle 100 is self-aligned with flow channel
95 to align nozzle channel 106 with flow channel 95. Particle 145
can be sorted with improved precision.
[0101] In flow cell 90 according to the present embodiment, a
second distance d.sub.2 between optical axis 120p of convex lens
120 and an end portion 107 of nozzle channel 106 close to flow
channel 95 is less than or equal to 2.0 mm in a cross section
defined by a first direction (z direction) in which flow channel 95
extends and a second direction (x direction) in which optical axis
120p of convex lens 120 extends. Hence, nozzle channel 106 is
disposed close to optical axis 120p of convex lens 120. The
break-off point at which jet flow 140 is broken off into droplet
144 can be close to optical axis 120p of convex lens 120, whereby
the identification information that characterizes particle 145 can
be detected at a position closer to the break-off point. Particle
145 can be sorted with improved sorting precision.
[0102] A flow chamber 40 according to the present embodiment
includes: flow cell 90 according to the present embodiment; and a
chamber 41 attached to flow cell 90. A cavity 42 of chamber 41
communicates with flow channel 95. Since flow chamber 40 includes
flow cell 90, the identification information that characterizes
particle 145 can be detected with improved sensitivity and particle
145 can be sorted with improved sorting precision.
[0103] A particle sorting apparatus 30 according to the present
embodiment includes: flow chamber 40 according to the present
embodiment; and a detection optical system 123 optically coupled to
convex lens 120. Detection optical system 123 includes a detection
side lens optical system 124. Since particle sorting apparatus 30
of the present embodiment includes flow cell 90, the identification
information that characterizes particle 145 can be detected with
improved sensitivity and particle 145 can be sorted with improved
sorting precision.
[0104] Particle sorting apparatus 30 according to the present
embodiment further includes an alignment unit 80 that aligns flow
channel 95 with detection side lens optical system 124. Since flow
channel 95 is aligned with detection side lens optical system 124
using alignment unit 80, particle sorting apparatus 30 can detect,
with improved sensitivity, the identification information that
characterizes particle 145.
[0105] Particle sorting apparatus 30 according to the present
embodiment further includes an imaging unit 137 and a controller
170. Imaging unit 137 is optically coupled to detection side lens
optical system 124. Controller 170 controls alignment unit 80 based
on an output from imaging unit 137. Hence, particle sorting
apparatus 30 can detect, with improved sensitivity, the
identification information that characterizes particle 145.
[0106] Particle sorting apparatus 30 according to the present
embodiment further includes a housing 35 and a transparent window
member 121. Housing 35 includes a first space 37 to be sterilized.
Transparent window member 121 is hermetically fitted in an opening
36b of housing 35. Flow cell 90 and chamber 41 are disposed in
first space 37. Transparent window member 121 fluidly separates
detection side lens optical system 124 from first space 37. First
space 37 can be sterilized without causing damage in detection side
lens optical system 124. Further, with convex lens 120, working
distance WD (see FIG. 7) can be long. Therefore, even when
transparent window member 121 is disposed between convex lens 120
and detection optical system 123, detection optical system 123 can
be readily incorporated into particle sorting apparatus 30 without
transparent window member 121 mechanically interfering with
detection optical system 123.
Second Embodiment
[0107] With reference to FIG. 13 and FIG. 14, the following
describes a particle sorting apparatus 30b and a particle sorting
apparatus cartridge 180 according to a second embodiment. Particle
sorting apparatus 30b of the present embodiment includes a
configuration similar to that of particle sorting apparatus 30 of
the first embodiment, and is different therefrom mainly in the
following points.
[0108] In the present embodiment, housing 35 includes no first
space 37. Separation wall 36 partitions second space 38 and an
external space, which is an open space. Particle sorting apparatus
30b includes particle sorting apparatus cartridge 180. Particle
sorting apparatus cartridge 180 can be attached to and detached
from housing 35. Particle sorting apparatus cartridge 180 can be
discarded after finishing sorting particles 145 included in the
sample liquid. Accordingly, particles 145 included in the sample
liquid can be sorted without cross contamination and carryover.
[0109] Particle sorting apparatus cartridge 180 mainly includes a
cartridge case 181, flow chamber 40, a transparent window member
121, and sample collection members 154, 155. Particle sorting
apparatus cartridge 180 may further include waste liquid collection
member 156. Flow chamber 40 is contained in first space 37, which
is an internal space of cartridge case 181. First space 37 is a
closed space and first space 37 is maintained to be in a hermetic
state. First space 37 is sterilized by applying radiation or heat
thereto, and is maintained to be in the sterile state. Transparent
window member 121 is hermetically fitted in opening 181b of
cartridge case 181. Collection unit 153 (sample collection members
154, 155 and waste liquid collection member 156) is attached to
cartridge case 181. Specifically, collection unit 153 (sample
collection members 154, 155 and waste liquid collection member 156)
is hermetically fitted in opening 181d of cartridge case 181.
[0110] Particle sorting apparatus cartridge 180 further includes
sample liquid source unit 50 and first conduit 51. Particle sorting
apparatus cartridge 180 may further include sheath liquid source
unit 52 and second conduit 53. Sample liquid source unit 50, first
conduit 51, sheath liquid source unit 52, and second conduit 53 are
contained in first space 37. Sample liquid source unit 50, first
conduit 51, sheath liquid source unit 52, and second conduit 53 are
incorporated in first space 37 within a sterile space such as a
safety cabinet. Particle sorting apparatus cartridge 180 may
further include vibration electrode portion 61. Vibration electrode
portion 61 is inserted in opening 181a of cartridge case 181.
Opening 181a of cartridge case 181 is closed by vibration electrode
portion 61 and chamber 41. Particle sorting apparatus cartridge 180
may further include deflection plates 151, 152. Extension portions
151a, 152a of deflection plates 151, 152 are hermetically fitted to
opening 181c of cartridge case 181.
[0111] Particle sorting apparatus 30b and particle sorting
apparatus cartridge 180 according to the present embodiment
exhibits the following effects in addition to the effects of
particle sorting apparatus 30 according to the first
embodiment.
[0112] A particle sorting apparatus cartridge 180 according to the
present embodiment includes: a flow chamber 40, a cartridge case
181, a transparent window member 121, and a sample collection
member 154, 155. Cartridge case 181 contains flow chamber 40.
Transparent window member 121 faces convex lens 120 and is
hermetically fitted in an opening 181b of cartridge case 181.
Sample collection member 154, 155 collects a droplet 144 ejected
from flow cell 90 and is attached to cartridge case 181. Particle
sorting apparatus cartridge 180 is discarded after finishing
sorting particles 145 included in the sample liquid. According to
particle sorting apparatus 30b and particle sorting apparatus
cartridge 180 according to the present embodiment, particles 145
included in the sample liquid can be sorted without cross
contamination and carryover.
Third Embodiment
[0113] With reference to FIG. 15 and FIG. 16, the following
describes flow cell 90, flow chamber 40, and a particle sorting
apparatus 30c according to a third embodiment. Flow cell 90, flow
chamber 40, and particle sorting apparatus 30c according to the
present embodiment include configurations similar to those of flow
cell 90, flow chamber 40, and particle sorting apparatus 30
according to the first embodiment, and are different therefrom
mainly in the following points.
[0114] In the present embodiment, housing 35 is provided with no
first space 37. Separation wall 36 partitions second space 38 and
an external space, which is an open space. Flow chamber 40 is
disposed in an external space. Sorting unit 150 (for example,
deflection plates 151, 152) and collection unit 153 (for example,
sample collection members 154, 155, and waste liquid collection
member 156) are disposed in the external space. As shown in FIG.
15, in the present embodiment, vibration electrode portion 61 (see
FIG. 1) and electrically conductive portion 65 (see FIG. 1) are in
one piece in vibration electrode 60c. Transparent window member 121
may be omitted.
[0115] As shown in FIG. 16, nozzle 100 is detachably coupled to
flow cell body portion 91. In one example, nozzle 100 may be
detachably attached to flow cell body portion 91 using a fixing
member 190 such as a screw, a threaded screw, or a pin. In another
example, nozzle 100 may be detachably screwed into flow cell body
portion 91.
[0116] Flow cell 90, flow chamber 40, and particle sorting
apparatus 30c according to the present embodiment exhibits the
following effects in addition to the effects of flow cell 90, flow
chamber 40, and particle sorting apparatus 30 according to the
first embodiment. Since nozzle channel 106 has a cross sectional
area smaller than that of flow channel 95, clogging with particles
145 included in the sample liquid is most likely to occur in nozzle
channel 106. In flow cell 90 of the present embodiment, nozzle 100
is detachably coupled to flow cell body portion 91. Accordingly,
when nozzle channel 106 is clogged with particle 145, it is not
necessary to exchange the whole of flow chamber 40 and only nozzle
100 may be exchanged. Even though flow chamber 40 cannot be
detached from housing 35, nozzle 100 can be exchanged readily at
low cost.
EXAMPLES
[0117] Examples will be described with reference to FIG. 17 and
FIG. 18. In the present example, particles 145 were sorted using
particle sorting apparatus 30 of the first embodiment.
Specifically, each of flow cell body portion 91 and convex lens 120
is composed of quartz. Convex lens 120 is welded to outer side
surface 92s of flow cell body portion 91. First angle .theta. is
43.3.degree. and convex lens 120 has a numerical aperture (NA) of
1.00. Second distance d.sub.2 between optical axis 120p of convex
lens 120 and end portion 107 of nozzle channel 106 is 1.0 mm. Flow
channel 95 has a cross sectional area of 160 .mu.m (first length
L.sub.1).times.150 .mu.m (second length L.sub.2), for example.
Nozzle channel 106 has a cross sectional area of 70 .mu.m.times.70
.mu.m, for example.
[0118] Particles 145 used in the present example are 10,000 beads
(SPHERO.TM. Rainbow Calibration Particles RCP-30-5). The beads
include: beads labeled with at least one of five types of
fluorophores from which fluorescences (light 117) having different
wavelengths are emitted; and beads not labeled with a
fluorophore.
[0119] In an Example 1, fluorescence data of the 10,000 beads in a
fluorescein isothiocyanate (FITC) channel was obtained. The
horizontal axis of the fluorescence data shown in FIG. 17
represents a fluorescence intensity, and the vertical axis
represents the number of beads. From the fluorescence data of
Example 1, an MESF of 75 was obtained as an index of the detection
sensitivity of particle sorting apparatus 30.
[0120] In an Example 2, fluorescence data of 10,000 beads in a
phycoerythrin (PE) channel was obtained. The horizontal axis of the
fluorescence data shown in FIG. 18 represents a fluorescence
intensity, and the vertical axis represents the number of beads.
From the fluorescence data of Example 2, an MESF of 28 was obtained
as an index of the detection sensitivity of particle sorting
apparatus 30.
[0121] MESF is an abbreviation of Molecular Equivalent of Soluble
Fluorophore, and means the number of fluorescence molecules per
bead in the present example. As the MESF is lower, particle sorting
apparatus 30 can detect, with higher sensitivity, the
identification information that characterizes the bead. In each of
Example 1 and Example 2, a high-sensitivity particle sorting
apparatus 30 having an MESF of less than or equal to 100 was
obtained.
[0122] The first to third embodiments disclosed herein should be
regarded as being illustrative and non-restrictive in any respect.
At least two of the first to third embodiments disclosed herein may
be combined as long as there is no contradiction. For example,
nozzle 100 in each of the first embodiment and the second
embodiment may be detachably coupled to flow cell body portion 91
in the same manner as nozzle 100 of the third embodiment. Vibration
electrode 60c of the third embodiment may be replaced with
vibration electrode 60 of the first embodiment. The scope of the
present invention is defined by the terms of the claims, rather
than the embodiments described above, and is intended to include
any modifications within the scope and meaning equivalent to the
terms of the claims.
REFERENCE SIGNS LIST
[0123] 30, 30b, 30c: particle sorting apparatus; 35: housing; 36:
separation wall; 36a, 36b, 36c, 161, 181a, 181b, 181c, 181d:
opening; 37: first space; 38: second space; 40: flow chamber; 41:
chamber; 42: cavity; 43: first inlet; 44: second inlet; 46:
surface; 50: sample liquid source unit; 51: first conduit; 52:
sheath liquid source unit; 53: second conduit; 54: filter; 60, 60c:
vibration electrode; 61: vibration electrode portion; 62: first
flange portion; 63: first shank portion; 63a: end surface; 64:
protrusion; 65: electrically conductive portion; 66: second flange
portion; 67: second shank portion; 68: recess; 70: insulation
sleeve; 72: sealing member; 74: vibration element; 76: charge
supply unit; 78: movable member; 79: fixing portion; 80: alignment
unit; 90: flow cell; 91: flow cell body portion; 92a: first end
portion; 92b: second end portion; 92s: outer side surface; 93:
nozzle receiving portion; 94: tapered surface; 95: flow channel;
96: end portion; 100: nozzle; 101: tapered surface; 103: flange
portion; 104: third end portion; 105: nozzle cavity portion; 106:
nozzle channel; 107: end portion; 108: tapered channel; 110: light
source unit; 110a, 110b, 110c, 110d, 110e, 110f, 110g: laser unit;
111: excitation light; 112: optical path conversion unit; 117:
light; 120: convex lens; 120p: optical axis; 121: transparent
window member; 123: detection optical system; 124: detection side
lens optical system; 124a, 124b, 124c, 124d, 124e, 124f, 124g,
124h, 124i, 124j, 124k: lens; 130: optical fiber array; 130f:
optical fiber; 131: wavelength division unit; 131f: wavelength
filter; 131g: reflective mirror; 132: light detection unit; 132f:
light detector; 134: reflective member; 135: reflective member
driving unit; 137: imaging unit; 140: jet flow; 144: droplet; 145:
particle; 150: sorting unit; 151, 152: deflection plate; 151a,
152a: extension portion; 153: collection unit; 154, 155: sample
collection member; 156: waste liquid collection member; 160:
connector; 162: O ring; 170: controller; 180: particle sorting
apparatus cartridge; 181: cartridge case; 190: fixing member; NA:
numerical aperture; WD: working distance.
* * * * *