U.S. patent application number 17/678590 was filed with the patent office on 2022-08-04 for optical system for capillary electrophoresis.
The applicant listed for this patent is Life Technologies Corporation. Invention is credited to Kevin MAHER.
Application Number | 20220244218 17/678590 |
Document ID | / |
Family ID | 1000006272398 |
Filed Date | 2022-08-04 |
United States Patent
Application |
20220244218 |
Kind Code |
A1 |
MAHER; Kevin |
August 4, 2022 |
OPTICAL SYSTEM FOR CAPILLARY ELECTROPHORESIS
Abstract
A system for conducting a capillary electrophoresis assay
includes a light source, an interface, and an illumination optical
system. The light source is configured to provide a source beam of
electromagnetic radiation. The interface is configured to receive a
plurality of capillaries containing one or more target molecules or
sequence of molecules. The illumination optical system is
configured in use to produce a plurality of output beams from the
source beam and to direct each of the output beams to corresponding
capillary of the plurality of capillaries.
Inventors: |
MAHER; Kevin; (Grass Valley,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Life Technologies Corporation |
Carlsbad |
CA |
US |
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|
Family ID: |
1000006272398 |
Appl. No.: |
17/678590 |
Filed: |
February 23, 2022 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15124013 |
Sep 6, 2016 |
11280759 |
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PCT/US2015/019280 |
Mar 6, 2015 |
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17678590 |
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61949961 |
Mar 7, 2014 |
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61949914 |
Mar 7, 2014 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G01N 2201/062 20130101;
G01N 27/44791 20130101; G01N 21/645 20130101; G01N 2021/6417
20130101; G01N 27/44721 20130101; G01N 2021/6484 20130101 |
International
Class: |
G01N 27/447 20060101
G01N027/447; G01N 21/64 20060101 G01N021/64 |
Claims
1. A system for conducting a capillary electrophoresis assay, the
system comprising: a light source configured to provide a plurality
of output beams of electromagnetic radiation; an interface
configured to receive a plurality of capillaries containing one or
more target molecules or sequence of molecules; an illumination
optical system configured in use to direct each of the plurality of
output beams to a corresponding capillary of the plurality of
capillaries; a spectrometer comprising a plurality of fibers,
wherein each fiber is associated with a corresponding one of the
capillaries, and wherein radiation from the capillaries is
dispersed by wavelength onto an array detector; and an emission
optical system configured to produce a plurality of spectrum
simultaneously at the array detector, each spectrum corresponding
to a respective capillary from the plurality of capillaries.
2. The system of claim 1, wherein the illumination optical system
comprises at least one of a beam divider configured to produce the
plurality of output beams, a diffractive optical element configured
to produce the plurality of output beams, or a holographic optical
element configured to produce the plurality of output beams.
3. The system of claim 1, wherein, during use, the system produces
a plurality of output beams including at least four beams.
4. The system of claim 1, wherein, during use, the system produces
a plurality of output beams and each of the plurality of output
beams is characterized by an elliptical cross-section.
5. The system of claim 1, wherein, during use, the system produces
a plurality of output beams and each of the plurality of output
beams is parallel to the other output beams.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application
Ser. No. 15/124,013 filed on Mar. 6, 2015, which claims priority to
U.S. Provisional Application No. 61/949,914 filed on Mar. 7, 2014,
all of which are incorporated herein by reference in their
entirety.
FIELD
[0002] The present invention relates generally to a systems,
devices, and methods for performing multi-capillary electrophoresis
or similar assays, tests, or experiments, and more specifically to
optical systems, devices, and methods for performing
multi-capillary capillary electrophoresis or similar assays, test,
or experiments.
BACKGROUND
[0003] Capillary electrophoresis devices generally provide certain
major components that include, for example, a capillary channel or
array of channels, a separation medium source for providing a
medium that may flow through the capillaries (e.g., a polymer
fluid), a sample injection mechanism, an optical detector system or
component, electrodes for producing an electric field, an anode
buffer source on one end of the capillaries, and a cathode buffer
source on the other end of the capillaries. Capillary
electrophoresis devices generally also provide various heating
components and zones to regulate the temperature of many of the
aforementioned components. Regulating the temperature of many of
these components can improve quality of results.
[0004] Current capillary electrophoresis devices use multiple
structures to house these components and connect or couple these
structures together to provide a working capillary electrophoresis
device. Using multiple structures has disadvantages. It is
therefore desirable to provide a capillary electrophoresis
apparatus with a reduced number of interconnected structures to
reduce the number of necessary heating zones, reduce user handling
of the structures, reduce likelihood of component failure, and
reduce introduction of bubbles and other artifacts into the
apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 illustrates a schematic representation of a cartridge
according to embodiments of the present disclosure.
[0006] FIG. 2 illustrates a capillary array design in accordance
with various embodiments of the present disclosure.
[0007] FIGS. 3A-3C illustrate cross section views of capillary
array designs in accordance with various embodiments of the present
disclosure.
[0008] FIG. 4 illustrates schematic interior side and top views of
a horizontal capillary array cartridge in accordance with various
embodiments of the present disclosure.
[0009] FIG. 5 illustrates details of a system in accordance with
various embodiments of the present disclosure.
[0010] FIG. 6 illustrates relative positioning of beams and
capillaries in accordance with various embodiments of the present
disclosure.
[0011] FIG. 7 illustrates cross section views of relative
positioning of beams and capillaries in accordance with various
embodiments of the present disclosure.
[0012] FIG. 8 illustrates a ribbon configuration of a capillary
array in accordance with various embodiments of the present
disclosure.
[0013] FIG. 9 illustrates alignment features of a capillary array
in accordance with various embodiments of the present
disclosure.
[0014] FIGS. 10A-10B illustrate schematic representations of a
capillary array holder in accordance with various embodiments of
the present disclosure.
[0015] FIGS. 11A-11B illustrate a capillary array holder in
accordance with various embodiments of the present disclosure.
[0016] FIG. 12 illustrates a schematic representation of a
capillary electrophoresis system in accordance with various
embodiments of the present disclosure.
DETAILED DESCRIPTION
[0017] As used herein, the term "radiant source" refers to a source
of electromagnetic radiation, for example, a source of
electromagnetic radiation that is within one or more of the
visible, near infrared, infrared, and/or ultraviolet wavelength
bands of the electromagnetic spectrum. As used herein, the term
"light source" refers to a source of electromagnetic radiation
comprising a spectrum comprising a peak or maximum output (e.g.,
power, energy, or intensity) that is within the visible band of the
electromagnetic spectrum.
[0018] Referring to FIG. 1, in certain embodiments, a capillary
assembly, holder, ribbon, cartridge, or the like comprises a
capillary array, a cathode, an electrode sleeve, the polymer/buffer
source, and polymer introduction mechanism (illustrated as a
syringe pump). The cathode end of the capillaries may be provided
outside the cartridge, for example, so that the cathode capillary
ends can move from the sample (for loading of sample to capillary)
to buffer (for insertion of the cathode end into the buffer).
[0019] Referring to FIG. 2, a capillary array is located within a
cartridge or holder in accordance with various embodiments of the
present invention. The figure illustrates, by way of example, a
4-capillary array comprising a capillary array and a holder
cartridge. In certain embodiments, the cartridge may include more
than four capillaries, for example, 8, 10, 12, 16, or more
capillaries, for example, to provide higher throughput or shorter
assay runs. The cartridge or holder guides the shape of the
individual capillaries in the array within the cartridge assembly
such that injection ends, and a detector region and a high-pressure
polymer inlet are formed. As illustrated in FIG. 4, the capillaries
may be spaced closer together over a detector region, for example,
to provide efficient more efficient way of providing optical
detection during a test, experiment, run, or assay.
[0020] FIG. 3 depicts a capillary array in accordance with
embodiments of the current invention. The capillary array comprises
a plurality of square capillaries, for example, as plurality of
square flexible fused silica capillaries that can be individually
fitted with injection-needle. In certain embodiments, the square
capillaries may be shaped stainless steel electrodes to perform
electro-kinetic sample injection. As seen in FIG. 3B, the capillary
array may be illuminated by a single beam of light or
electromagnetic illumination, for example, provided by a laser
beam. In such embodiment, optical data may be obtained by viewing
the capillary array from the top or bottom of the figure.
Advantageously, the square capillaries may be configured such that
deviations in the illuminating beam cross-section as it passes
through the square capillaries are less deviations produced by
circular capillaries having the same refractive index and fluid
contained within the capillaries.
[0021] Referring to FIG. 4, which depicts schematic interior view
of horizontal capillary array, a cartridge may be provided in
accordance with various embodiments to hold the capillary array and
to interface with various other elements of a capillary system. The
cartridge includes the capillary array and a polymer/buffer
reservoir, where the polymer serves both as a polymer for the
capillaries and an anode buffer. The cartridge also includes a
single bend in the injection-to-detection region to allow access of
the sample inlet/cathode end to sample for loading, capillary
cleaner (e.g., water), and buffer for electrophoresis. The
cartridge may be configured to provide temperature control of at
least 80% of the capillary path. The cartridge also includes an
optical access portion at a location where the capillaries are
closer together and near the introduction of the polymer/buffer
used during operation of the cartridge and associated system.
[0022] Further details of the construction and operation of the
capillary array systems shown in FIGS. 1-4 are provided in the
patent application identifiable as Life Technologies docket number
LT00897US (U.S. patent application Ser. No. 15/124,168), now issued
as U.S. Pat. No. 10,274,460, all of which are incorporated herein
by reference in their entirety.
[0023] Referring to FIG. 5, certain embodiments of the present
invention comprise a system or instrument for performing a
capillary electrophoresis or similar assays, test, or experiment.
The system comprises a capillary array that is contained, held, or
housed within a capillary array holder, ribbon, cartridge, or the
like. The capillary array comprises a plurality of capillaries or
channels, for example, at least two capillaries or channels. In the
illustrated embodiment, the capillary array comprises 4 capillaries
or channels; however, the array may include more than four
capillaries, for example, 8, 10, 12, 16, or more capillaries, for
example, to provide higher throughput or shorter assay runs.
[0024] The system in the illustrated embodiment shown in FIG. 5
also comprises an optical system that generally comprises a light
source, a beam shaper, a beam divider, excitation and emission
optical components, and a spectrometer system. The optical system
may be configured in different embodiments for use with one or more
types of capillary arrays, capillary holders, ribbons, cartridges,
or the like, including, but not limited to the cartridges shown in
FIGS. 1-3 or any of those disclosed in the Life Technologies'
LT00897 PRO provisional application identified above. The system
may also include an electronic interface such as an internal and/or
external computer or processor. The external computer may be
coupled to other portions of the system via a wired or wireless
connection and/or via a network or cloud-based system. The computer
may be configured to operate one or more portions of the system,
including but not limited to the light source, spectrometer,
capillary array holder, chemical and/or electrical elements of the
capillary array and related components, reagents, samples, or the
like.
[0025] The light source by be a laser, light emitting diode (LED),
LED array, xenon or halogen lamp, incandescent light source, or the
like. In certain embodiments, the light source is a diode laser,
for example, a diode laser having a wavelength of or about 505
nanometers. The light source may provide a single wavelength or
wavelength range. Alternatively, the light source may be configured
to provide more than one wavelength or wavelength range, either
simultaneously or in a temporally sequential manner. For example,
the light source may comprise a plurality of light sources having
different wavelengths or wavelength ranges, or may comprise a
broadband source including one or more optical or dichroic
filters.
[0026] Light from the light source may pass through a beam
conditioner or beam shaper to provide one or more predetermined
optical characteristic including, but not limited to, a beam
diameter(s), a beam shape (e.g., circular or elliptical), a
predetermined intensity or power profile (e.g., constant, top hat,
Gaussian, etc.). Additionally, or alternatively, the beam
conditioner may comprise a homogenizer, for example, configured to
blend different color light sources and/or to provide a more even
illumination cross-section of the output beam. In the illustrated
embodiment, the beam shaper is configured to produce or provide a
beam that has an elliptical cross section or shape. To produce or
provide the elliptical shape, the beam shaper may comprise an
anamorphic beam shaper. The anamorphic beam shaper may comprise one
or more cylindrical lenses configured to produce a beam having an
elliptical cross section, that is, in which the beam cross section
is wider in one axis than in the other perpendicular axis.
Alternatively, the beam shaper may comprise a Powel lens, for
example, configured to provide a line focus and/or an elliptical
beam cross section in which an intensity or power over a cross
section of the beam uniform, or nearly uniform.
[0027] In addition, the beam shaper may be configured so that any
diameter of the beam is greater than or less than the diameter of
the beam entering the beam shaper. In the illustrated embodiment,
the beam exiting the beam shaper is collimated. In certain
embodiments, the beam entering the beam shaper is also collimated,
while in other embodiments, the beam entering the beam shaper is
not collimated, but is collimated by the beam shaper.
[0028] In the illustrated embodiment, the output from the beam
shaper enters a beam divider configured to produce a plurality of
identical or similar beams from a single input beam into the beam
divider. As an example, the beam divider may comprise one or more
diffractive optical elements, holographic optical elements, or the
like, that is configured to produce or provide four elliptical
beams for illuminating each of the four capillaries shown in FIG.
5. In the illustrated embodiment, the four beams have the same or a
similar cross-section, and each beam diverges at a different angle
relative to a system optical axis or general directions of light
propagation. Alternatively, the beam divider may be configured to
produce a plurality of beams that are parallel to one another or
that converge relative to one another. In the illustrated
embodiment, the beams out of the beam divider are collimated;
however, some or all of the beams may alternatively be converging
or diverging as they leave the beam divider.
[0029] The diverging beams from the beam divider in the illustrated
embodiment are reflected by a mirror and directed toward the
capillary array. Additional mirrors and/or diffractive elements may
be included as desired to direct the four beams toward the
capillary array, for example, to meet packaging constraints. The
beams continue to diverge after reflection off the mirror until
they are received by the lens L1 shown in FIG. 5. The mirror may be
a dichroic mirror, or the like, which may be configured to reflect
light at a predetermined wavelength or light over a predetermined
wavelength range, while transmitting light or other electromagnetic
radiation that is outside the predetermined wavelength or
wavelength range. In some embodiments, the mirror is a dichroic
mirror having more than one predetermined wavelength or wavelength
range, for example, when the light source comprises more than one
distinct wavelength or wavelength range. In the illustrated
embodiment, the excitation beams are reflected by the mirror, while
emitted light or radiation (e.g., fluorescent light or radiation)
from the capillary array is transmitted or largely transmitted by
the mirror. Alternatively, the location of the capillary array may
be located along the optical axis of the beam divider and the
mirror may be configured to transmit, or largely transmit, the
excitation beams, while reflecting emitted light or radiation from
the capillary array.
[0030] In the illustrated embodiment, the elliptical beams
originating from the beam divider are each collimated as they enter
the lens L1, but are diverging relative to one another. In such
embodiments, the lens L1 may be configured focus each of the
individual beam to a location at or near a respective capillary, as
illustrated in the magnified view of FIG. 5. In addition, the lens
L1 and the beams out of the beam divider may be configured such
that the individual beams are each collimated relative to one
another (e.g., the four beams in FIG. 5 may all travel parallel to
one another after exiting the lens L1).
[0031] In certain embodiments, at least some of the capillaries
include one or more fluorescent dyes, probes, markers, or the like,
which may be selected to produce a fluorescent signal proportional
to an amount of one or more target molecules or sequences of
molecules present at a given time. The fluorescent signal(s),
light, or radiation produced within any or all of the capillaries
may be directed back through the lens L1 and the mirror so as to be
received by a spectrometer.
[0032] After passing through the lens L1, the fluorescent radiation
then propagates through one or more emission filters and a second
lens L2 is used to re-image the radiation at an image plane. A
detector, which may include an array detector such as a
Charge-Coupled Device (CCD) or a Complementary Metal-Oxide
Semiconductor (CMOS) detector, or the like, may be located at or
near the image plane for further processing. In the illustrated
embodiment, the radiation at the image plane is received by
spectrometer, which may be configured to separate the signal
created by different fluorescent dyes, probes, markers, for
example, created by dyes, probes, markers corresponding to the DNA
or RNA bases (e.g., adenine, thymine (or uracil), cytosine, and
guanine).
[0033] The spectrometer may comprise a plurality of fibers, where
each fiber may be associated with (e.g., receive radiation from) a
corresponding one of the capillaries from the capillary array.
Using the fibers, radiation from the capillaries is then
transferred into the spectrometer, where it is dispersed by
wavelength onto a detector (e.g., an array detector such as a CCD
or CMOS detector or the like). In the illustrated embodiment, the
plurality of fibers comprises two fiber bundles, FB1 and FB2, each
bundle containing a plurality of fibers (two fibers each in the
illustrated embodiment). The radiation from the fibers of FB1
enters on one side of the spectrometer and radiation from the other
fibers in FBs enters on another side of the spectrometer. In this
manner, the spectrum from each of the fibers (capillaries) is
directed on a different portion of the detector. This configuration
has been found to advantageously allow the spectrum from each of
multiple capillaries to be produced and detected simultaneously on
a single or reduced number of array detectors.
[0034] The emission filter located between lenses L1 and L2 may be
configured block or attenuate light from the light source, thereby
eliminating or reducing the about of light from the light source
that is receive by the spectrometer. In certain embodiments, the
focal length of lenses L1 and L2 are selected to produce a
magnification of the capillaries or light from the capillaries that
is different than one (e.g., to produce a magnified or demagnified
image). For example, the lens L1 may be selected to have a
numerical aperture (NA) that is twice the NA of the lens L2,
resulting in a system magnification of two. In certain embodiments,
lens L1 has an NA of 0.4 and lens L2 has an NA of 0.2. In some
embodiments, the focal length or NA of lenses L1, L2 may be
selected to (1) provide a focal spot, or focal point, at or near
the capillary array that has a predetermined size or diameter and
(2) simultaneously providing an NA that is matched to the NA of the
spectrometer and/or the NA of the optical fiber system used to
transfer light into the spectrometer.
[0035] As shown in FIG. 5, the entire optical system and cartridge
may be located within a common instrument housing. The common
housing may include an opening or port to allow transfer of
radiation or light from the capillary array to the spectrometer.
The spectrometer may be contained in a separate housing, as shown
in FIG. 5, or included inside the same instrument housing as the
optical system. In contrast to the embodiment shown in FIG. 5, the
capillary array and/or some of associated hardware may be located
outside the instrument housing, in which case an interface with the
instrument may be provided via an opening or port in the instrument
housing.
[0036] Referring to FIG. 6, the elliptical cross section of each of
the beams may be oriented so that the long axis or dimension is
oriented perpendicular or nearly perpendicular to an axis of the
associated capillary. This orientation of the beam and focus has
been found to advantageously reduce the sensitivity of the
alignment of the capillary array to the beams. In the illustrated
embodiment shown in FIG. 6, the long diameter of the beam focus is
less than an inner diameter of an individual capillary.
Alternatively, as illustrated in FIG. 7, the long diameter of the
beam focus may be larger than the inner diameter of the individual
capillary. FIG. 7 also illustrates the diameters and pitch of the
capillaries within the array for certain embodiments. As seen in
the illustrated embodiment, the inner diameter of the capillary is
50 micrometers, while the focused beam has a diameter of about 100
micrometers.
[0037] Referring to FIGS. 8 and 9, a ribbon configuration of the
capillary array is illustrated, which may be used in certain
embodiments of the instrument shown in FIG. 5. The ribbon may be
configured to interface directly with the instrument or may
alternatively be disposed within a carrier or cartridge that
interfaces with and/or is coupled to the instrument. As shown in
FIG. 9, the ribbon may comprise a V-groove block, fixture, or
arrangement that is configured to receive the individual
capillaries so as to provide a predetermined alignment and/or
spacing between the capillaries of the array. A snap feature is
shown that may be configured to help maintain the capillaries
within the ribbon. The V-groove block may also comprise alignment
tabs or similar features that are used to engage the instrument in
a way that provides a known tolerance in the alignment of the
capillaries with the associated light or radiation beams. For
example, the tabs may be configured to provide a predetermined
tolerance of the lateral position of the capillaries relative to
the beams and/or a predetermined angular tolerance.
[0038] Referring to FIGS. 10A-B and FIGS. 11A-B, in certain
embodiments, a capillary array holder or cartridge comprises a
dynamic mount that generally constrains or restricts movement in
all but one direction. A seen in the illustrated embodiment, the
dynamic mount allows movement of the capillary array in a direction
perpendicular to a length of the individual capillaries, while
eliminating or restricting motion in other directions and/or
eliminating or restricting angular positioning or motion of the
capillary array. As shown in FIGS. 10B and 11B, the dynamic mount
advantageously allows a pin of known location relative to the
illuminating beams to move the capillary array into a predetermined
position relative to the illuminating beams. Such a configuration
may also be configured to reduce or eliminate twisting of the
capillary array during an alignment process.
[0039] As opposed to the above passive alignment mechanisms
described above, in certain embodiments, alignment of the
capillaries and/or capillary array is accomplished using an active
alignment. For example, a signal from one or more of the
capillaries may be used to determine the degree of alignment
between the illuminating beams and the capillaries. The signal
produced during an alignment process or step may be used in
conjunction with a movement mechanism that moves one or more of the
capillary array, one or more individual capillaries, one or more
illumination beams, the capillary cartridge, or some portion of a
frame or support located within the instrument housing. A series of
optical measurements may be made as relative motion is induced
between one or more of the capillaries and one or more illuminating
beams. In this manner, the degree of alignment may be determined
and/or chosen based on a monitoring of the strength of one or more
signals produced as the relative position between one or more of
the capillaries and one or more of the illumination beams is
changed. In certain embodiments, such an active alignment process
can be accomplished by using a capillary wall scatter signature to
find and/or peak a Raman spectrum produced by a medium (e.g.,
water).
[0040] In some embodiments, two or more of the illumination or
excitation beams into the different capillaries shown in FIGS. 5-7
are independently produced using separate light or radiation
sources for different illumination beams. Additionally, or
alternatively, the independently produced illumination or
excitation beams into the capillaries may utilize different optical
elements for each--for example, separate beam shapers, separate
mirror, separate lenses, and the like. In such embodiments, a
common light source may be utilized, but different split into
different optical paths that each have their own separate optical
and/or conditioning elements. In such embodiments, each separate
illumination or excitation beam may utilize a passive or active
process and/or hardware for aligning each beam to its respective
capillary--for example, using one or more of the alignment devices
or procedures discussed above. Such systems and methods
advantageously allow greater flexibility in the design and
construction of the capillaries and associated cartridge or
holder.
[0041] Referring to FIG. 12, in certain embodiments, the
illumination and imaging optics are located along entirely
different paths. In certain embodiments, the system in FIG. 12
comprises two or more capillaries and multiple LEDs or other light
sources to produce plural illumination or excitation beams that
illuminate corresponding capillaries of the two or more
capillaries. Additionally, or alternatively, each of the two or
more capillaries may have its own spectrometer. Such systems
advantageously allow greater flexibility in the design and
construction of the capillaries and associated cartridge or
holder.
[0042] The above presents a description of the best mode
contemplated of carrying out the present invention, and of the
manner and process of making and using it, in such full, clear,
concise, and exact terms as to enable any person skilled in the art
to which it pertains to make and use this invention. This invention
is, however, susceptible to modifications and alternate
constructions from that discussed above which are fully equivalent.
Consequently, it is not the intention to limit this invention to
the particular embodiments disclosed. On the contrary, the
intention is to cover modifications and alternate constructions
coming within the spirit and scope of the invention as generally
expressed by the following claims, which particularly point out and
distinctly claim the subject matter of the invention.
* * * * *