U.S. patent application number 12/876189 was filed with the patent office on 2010-12-30 for upon a cartridge for containing a specimen sample for optical analysis.
This patent application is currently assigned to VERIDEX, LLC. Invention is credited to Tor Alden, Michael Kagan, Jerry Prohaska, Galla Chandra Rao.
Application Number | 20100326587 12/876189 |
Document ID | / |
Family ID | 32324979 |
Filed Date | 2010-12-30 |
United States Patent
Application |
20100326587 |
Kind Code |
A1 |
Kagan; Michael ; et
al. |
December 30, 2010 |
UPON A CARTRIDGE FOR CONTAINING A SPECIMEN SAMPLE FOR OPTICAL
ANALYSIS
Abstract
An improved cartridge for holding a fluid sample with a small
volume is disclosed herein. The cartridge has a test chamber and a
vestibule through which the test fluids are inserted into the test
chamber. Improved grips are flared-out to aid manipulation. The
handle portion is reinforced to prevent flexing, and a
prefabricated trough along the edge of the land surface prevents
introduction of the adhesive into the region for analysis. The
cartridge has a stopper having a dual sealing mechanism, which
seals the test chamber inlet between the vestibule and the test
chamber, and the mouth of the vestibule so that when the stopper is
in place, the test chamber is closed to the admission of air or
other contaminants. The vestibule is similarly closed against
escape of the overflow from the test chamber. The stopper is
composed of a single elastomer. An improved locking mechanism has
two flexible walls on either side of the handhold that locks into
their respective keepers on the cartridge to provide a secure lock.
Additionally, an improved method for loading the cartridge allows
for an even distribution of magnetically responsive particles
contained within a fluid sample to be viewed in an array through
the optically clear land surface portion of the cartridge.
Inventors: |
Kagan; Michael; (Doylestown,
PA) ; Rao; Galla Chandra; (Princeton, NJ) ;
Prohaska; Jerry; (Huntingdon Valley, PA) ; Alden;
Tor; (Basking Ridge, NJ) |
Correspondence
Address: |
PHILIP S. JOHNSON;JOHNSON & JOHNSON
ONE JOHNSON & JOHNSON PLAZA
NEW BRUNSWICK
NJ
08933-7003
US
|
Assignee: |
VERIDEX, LLC
Raritan
NJ
|
Family ID: |
32324979 |
Appl. No.: |
12/876189 |
Filed: |
September 6, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11294012 |
Dec 5, 2005 |
7815863 |
|
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12876189 |
|
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|
10303309 |
Nov 25, 2002 |
7011794 |
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11294012 |
|
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Current U.S.
Class: |
156/99 |
Current CPC
Class: |
B01L 2200/0689 20130101;
B01L 2200/0642 20130101; G01N 35/0098 20130101; B01L 3/508
20130101; B01L 2300/046 20130101; Y10T 436/2575 20150115; B01L
2300/042 20130101; G01N 21/11 20130101 |
Class at
Publication: |
156/99 |
International
Class: |
B32B 17/10 20060101
B32B017/10 |
Claims
1. A process for the manufacture of a cartridge having an optically
clear land surface affixed to a plastic body, the process
comprising: (a) molding a plastic edge so as to be in contact with
said optically clear land surface such that said plastic edge is
shaped as a small shelf for seating outer portion of said land
surface, (b) shaping the entire contact area of said small shelf
into a small trough such that said small trough runs along said
outer portion of land surface, (c) filling said small trough with
an optically clear adhesive along entire said contact area, (d)
placing said outer portion of land surface on said small trough
such that said adhesive is allowed to wick down said small trough
and away from all possible optical paths, and (e) exposing said
adhesive to UV light such that said optically clear land surface
becomes affixed to said plastic edge.
2. A process according to claim 1 wherein said optically clear
adhesive is a non-fluorescent compound which binds after exposure
to UV light.
3. A process according to claim 1 wherein said optically clear
adhesive is selected from the group consisting of
pressure-sensitive adhesives, heat cured adhesives, and adhesives
activated by ultraviolet light.
4. A process according to claim 1 wherein said optically clear
adhesive is an adhesive activated by ultraviolet light
5. A process according to claim 1 wherein said optically clear land
surface is glass.
6. A process according to claim 5 wherein said glass is cut to
tight tolerances at around 0.5 mm thick.times.31 mm in length and 5
mm in width.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of Ser. No. 11/294,012,
filed Dec. 05, 2005, now allowed which is a divisional application
of U.S. Pat. No. 7,011,794, issued Mar. 14, 2006.
FIELD OF THE INVENTION
[0002] The present invention is an improvement upon an earlier
filed application relating to a cartridge having a chamber for
containing a specimen sample used in optical analysis
(PCT/US02/04124; U.S. Pat. No. 6,861,259; U.S. Ser. No.
10/988,057). One improvement enables the use of the cartridge in a
manner that is more practical and less expensive for analysis of
small biological samples, particularly blood. Another improvement
enables a more efficient and uniform distribution of magnetically
labeled target components within a sample prior to analysis.
BACKGROUND OF THE INVENTION
[0003] When performing optical analysis on specimens in liquid
suspension, it is customary to discard the specimen after analysis.
For rare cells, however, it is often desirable to preserve the
liquid specimen for further testing or for use in further
procedures. In certain procedures, it is desirable to select a
specimen of a relatively small sample (less than 400 ul) from
larger volumes (up to 100 ml), and it is likely that the volume of
the specimen, which may be extracted from such a sample, is
limited, making it especially important to avoid destruction of the
specimen or any substantial part thereof. It is likewise important
to avoid contamination of the specimen and to avoid conditions
leading to deterioration of the specimen or impairment of
analysis.
[0004] One cause of inconsistent optical analysis from sample to
sample is a lack of uniform distribution of the magnetic particles
and the magnetically labeled target components within the fluid
sample due to gravitational forces. This pooling affect occurs when
the sample is first placed into the cartridge chamber. Unless the
chamber is perfectly horizontal, the magnetic particles, together
with the magnetically labeled target components tend to settle
toward the lower portions of the chamber. When the chamber is
loaded in the vertical position, a preferred loading position, the
magnetic particles and the magnetically labeled target components
settle toward the distal portion of the chamber. Consequently, the
magnetic particles and the magnetically labeled target components
do not distribute uniformly across the optical window, causing the
inability to perform optical analysis.
[0005] Another issue in the development of the cartridge and
stopper is to provide a structure that is relatively inexpensive to
manufacture (PCT/US02/04124), yet functions satisfactorily in
preserving the sample. Construction, from two different plastic
materials such as that described in the stopper component of the
parent application, are expensive to manufacture and complicated in
their construction. Since specimen samples are stored in a manner
to prevent deterioration, there also is a need to maintain the
locking feature so as to provide a proper seal against
contamination and air. Thus, a stopper that would incorporate the
benefits of a single elastomer composition together with a locking
mechanism to minimize deterioration of the sample is needed.
[0006] In conjunction with a need to improve sample storage for
optical analysis, there is a need to increase the ease and speed of
manipulations of the cartridge. A better grasp on the cartridge
would prevent unnecessary cartridge flexing that could allow air to
enter the test chamber, and would provide more secure transfer of
the cartridge from the loading position to the platform for
analysis.
SUMMARY OF THE INVENTION
[0007] As can be seen from the discussion, above, there is a need
to further improve upon select aspects of U.S. Patent Application
PCT/US02/04124.
[0008] The present application describes a collection chamber
designed to isolate a small sample for analysis and to preserve the
sample for additional testing. Specifically, this collection device
enables the exclusion of air as bubbles or other forms from the
sample chamber, but does not provide a low cost chamber with
uniform analyte distribution for analysis.
[0009] U.S. Pat. No. 5,246,669 discloses a sampling device for
collecting a small sample and mixing it with a test liquid. In this
patent, the device provides a pickup device, which extracts a small
sample from a larger quantity of solid or semi-solid material to be
tested. The device separates the small sample from the residue and
isolates the residue so as to avoid contamination of the small
sample or the surrounding atmosphere. The device does not provide
for salvaging either of the test sample or the residue and does not
have any provision for excluding air in the form of bubbles from
the test liquid.
[0010] In addition to the need to redesign the cartridge and
stopper, improved optical analysis is also obtained in the
manufacturing process of the cartridge of the invention. There is a
need to manufacture a cartridge that allows for a consistently
clear and uniform area for viewing. The sample circumvent problems
in the analysis of magnetically labeled target components,
particularly with respect to those target components located close
to the contact area between the cartridge dome and the optically
clear land surface interface. More specifically, interference from
adhesive used to join the optically clear land surface with the
rest of the cartridge results when the adhesive spreads onto the
optical path during the manufacture of the chamber. Thus, there is
a need to develop a process for affixing the optically clear land
surface in a way that prevents the introduction of adhesive onto
the optical analysis region.
[0011] Improving the ability to manipulate a chamber containing
magnetically labeled target components within a sample coupled with
the ability to display them in a uniform manner, all in a low cost
manner, enables the present invention to provide a consistent
platform for optical analysis.
[0012] Accordingly, the present invention provides an improvement
to a novel cartridge for use in optical analysis of specimens. As
with the original cartridge, the improved version has a test
chamber that contains the specimen for subsequent procedures,
provides a platform for optical analysis of the specimen without
loss of any substantial part thereof, and enables the specimen to
be retained in the cartridge test chamber in the absence of air
bubbles or other contaminants. The cartridge is also used in a
method for handling specimens enabling the specimen to be presented
in a test chamber for optical analysis without the risk for loss of
any substantial part of the specimen and without the risk of
inclusion of air bubbles or exposure to other deteriorating
conditions in the test chamber with the target components evenly
distributed for optical analysis.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a schematic representation of the cartridge and
receptacle having a pair of opposed magnetic poles made in
accordance with the present invention.
[0014] FIG. 2 is a front view of a cartridge embodying the present
invention and the associated improvements with its stopper in place
to illustrate the engagement of the stopper with the body of the
cartridge.
[0015] FIG. 3 is a view similar to FIG. 2 showing the stopper
removed from the body of the cartridge.
[0016] FIG. 4 is a cross-sectional (A), magnified cross-sectional
(B), and longitudinal-sectional (C) view. FIG. 4A and 4B are
cross-sectional views taken on the line 4A-4A of FIG. 3. FIG. 4B is
an enlarged cross-sectional view of the adhesive trough on the edge
of the shelf portion of the body juxtaposed to the optically clear
edge of the land surface. FIG. 4C is a longitudinal-section taken
on the line of 4B-4B of FIG. 3.
[0017] FIG. 5A, 5B, AND 5C are sectional views of the cartridge in
loading position illustrating the cooperation between the cartridge
body and the stopper to entrap the specimen in the cartridge in the
absence of air. FIG. 5A shows the stopper removed with the specimen
in place within the chamber and the vestibule. FIG. 5B is a view
similar to FIG. 5A showing the penetration of the probe of the
stopper into the buffer within the vestibule. FIG. 5C shows the
stopper in place closing both the port between the chamber and the
vestibule and the upper end of the vestibule.
[0018] FIG. 6 is a perspective view of the stopper shown in FIGS.
2-5.
[0019] FIG. 7 is an enlarged fragmentary sectional view of the
cartridge with the stopper operatively engaged with the body of the
cartridge.
DETAILED DESCRIPTION OF THE INVENTION
[0020] The device of the present invention has been improved to
limit significant settling of target components prior to loading,
thus enabling a uniform distribution of the array of magnetically
responsive particles and magnetically labeled target components
along the viewing surface. Because the biological sample is loaded
into the cartridge in the presence of a magnetic field, an equal
distribution of magnetically labeled target components is ensured.
Loading is accomplished by placing the cartridge vertically within
a magnetic field prior to sample loading. The sample is then
introduced into the cartridge chamber, closed with a stopper, and
maintained until analyzed. Optical analysis is completed without
settling and with a uniform distribution of target components that
remains consistent from sample to sample.
[0021] As with the cartridge from the parental application, the
specimen sample can be introduced into the test chamber of the
cartridge along with a buffer solution in which the respective
properties of the specimen and the buffer solution are such as to
provide an interface separating the buffer solution from the
sample. The sample chamber is elongated with a port at one end.
Preferably, the buffer solution is of a density less than or equal
to the density of the sample so that when the chamber is disposed
with the ported end upright, the buffer solution is positioned
above the interface and the sample is positioned below the
interface. During the filling of the chamber, any air or other
contaminants, which are less dense than the buffer solution, are
allowed to gravitate upwardly through the buffer solution towards
the port in the upper end of the chamber. The chamber is designed
with a vestibule containing an overflow reservoir capable of being
sealed both from the test chamber and the exterior environment. A
stopper is provided for sealing both ends of the vestibule through
its attached probe, which extends into the buffer solution above
the interface. As the stopper, through the probe, is engaged with
the port of the test chamber, the probe displaces the buffer into
the vestibule. The stopper now forms a primary seal, which closes
the test sample chamber from the vestibule. Subsequently, the
stopper forms a second seal to close the outside entrance of the
vestibule to prevent escape of the buffer from the vestibule. The
vestibule thus serves as an overflow receptacle. The first seal
closes the test chamber after any deleterious air bubbles in the
chamber have migrated into the vestibule. Thereafter, the second
seal closes the overflow chamber to retain the buffer solution
against loss with the simultaneous engagement of the stopper
through an improved clip mechanism.
[0022] Improvements on the stopper results in reduced expense and
increased ease of cartridge handling. The improved stopper is
composed of a single elastomer with a preferred durometer value of
about 60 to 90. The stopper is locked into position in the
cartridge by flexible walls so that when the second seal closes the
overflow chamber the walls are compressed until they snap outwardly
to position against their respective keeper elements. This
interaction allows the stopper to lock into place, making stopper
alignment with the chamber easier and making the stopper much more
difficult to remove after filling.
[0023] When in place, the stopper and handle permit the cartridge
to be griped and manipulated into position with the optical
detecting device in an orientation which positions the test chamber
so that the target cells are in a suitable position within the
field of observation for the detection equipment.
[0024] Grips on the cartridge used for manipulating the cartridge
into position have been improved by flaring-out the inward taper to
allow a more secure grasp and better control. Accordingly, the
cartridge may be easily mounted in a microscope or other detection
equipment to allow positioning of the target components in the
biological sample within the equipment's sample observation field.
Within the handle portion and between the grip areas, the cartridge
has improved support to prevent unintentional flexing thereby
affecting the established seals between the stopper and
cartridge.
[0025] Finally, a novel type of manufacture for the attachment of
the optical land surface to the plastic portion of the cartridge is
described. More specifically, a plastic edge is in contact with an
optically clear land surface, which is usually glass. The edge is
shaped as a small shelf to seat the land surface. The shelf spans
the entire area to be in contact with the land surface. A small
trough is positioned along the shelf, but within the area to be in
contact. A binding adhesive is introduced into the trough and along
the entire contact region. The binding adhesive is an optically
clear adhesive that is non-fluorescent and unable to react with the
sample. When the optically clear land surface is placed in contact
with the shelf, the adhesive is channeled away from the optical
path. This allows for a more reproducible and for a more consistent
observation during optical analysis. While any adhesive with the
characteristics described above will work, adhesives can be of a
pressure-sensitive type, heat cured type, or activated by
ultraviolet light.
[0026] Optical analysis of biological samples, especially rare
cells, requires a method and means to maintain the specimen in a
condition that would allow inexpensive and reproducible. The
improved sample cartridge and stopper, when used together, are
designed to avoid contamination of the biological sample, but with
an improved design and manufacture which allows for better control
during any manipulation prior to optical analysis, uniform
distribution of magnetically labeled target components for optical
analysis, and at a lower cost to produce.
[0027] One improvement in the preparation of the sample is to load
and store the cartridge assembly, either the parental or improved
version, within an applied magnetic field prior to sample filling
and optical analysis. The cartridge is positioned vertically before
loading within an applied magnetic field in preparation for sample
loading. The sample is introduced into the cartridge chamber within
the magnetic field, resulting in the prevention of any settling of
magnetically responsive particles and any magnetically labeled
target components. Accordingly, the magnetically labeled target
components are arranged in an evenly distributed, which is
consistently displayed from sample to sample. The magnetic field
prevents these same magnetically labeled target components from
clustering within one region of the cartridge prior to optical
analysis. Thus after insertion of the stopper into the cartridge,
the magnetically labeled target components of the biological sample
will remain stably positioned along the flat land surface of the
cartridge until removed from the magnetic field after analysis.
[0028] The cartridge and stopper of the improved invention are
particularly adapted for use in a detecting apparatus such as shown
in U.S. Pat. No. 6,013,532, which issued to Liberti et al. on Jan.
11, 2000, and described in a paper entitled "Optical Tracking and
Detection of Immunomagnetically Selected and Aligned Cells" by
Arjan G. J. Tibbe et al., Published in Nature Biotechnology, Vol.
17, Dec. 1999, pp1210-1213, both of which are incorporated by
reference herein. The cartridge and receptacle, shown schematically
in FIG. 1 of the patent, is effective to immobilize magnetically
labeled target entities, such as cells, within a fluid medium for
observation, analysis or manipulation. The magnetically labeled
target entities are deposited in a test chamber where they are
manipulated by a magnetic field to dispose the magnetically labeled
target entities in a monolayer along a wall of the test chamber. A
discussion of automated magnetic separation techniques is included
in U.S. Pat. No. 5,985,153 which issued to Gerald J. Dolan et al.
on Nov. 16, 1999, and in a paper entitled "Cell Analysis System
Based on Immunomagnetic Cell Selection and Alignment Followed By
Immunofluorescent Analysis Using Compact Disk Technologies" by
Arjan G. J. Tibbe et al., published in Cytometry, 43:31-37 (2001),
both of which are also incorporated herein by reference.
[0029] Referring to FIG. 1, an improved cartridge embodying the
invention is shown at 21 mounted in a receptacle 20 having a pair
of opposed magnetic poles, 22 and 23 which have a gap formed
therebetween. In the illustrated detecting apparatus, the
receptacle 20 is positioned horizontally in the path of the optical
system of the apparatus with the gap upwardly, but for other
applications the receptacle may be positioned vertically. In FIG.
1, the lower surfaces of the poles 22 and 23 are tapered toward the
gap so that magnetic field applied to the chamber is non-uniform
and has a substantially vertical gradient effect directed toward
the gap transverse to the longitudinal axis of the cartridge 21 to
urge magnetically-responsive particles and magnetically labeled
targets within the chamber towards the wall of the cartridge which
is substantially co-planar with the gap. The magnetically labeled
target entities are displayed as an orderly monolayer on the
interior surface of the test chamber, and an automated observation
system can be configured to provide relative motion between the
cartridge and the light-gathering elements of the observation
system in order to tract the collected magnetically labeled target
entities for automated enumeration, which can include spectral
analysis of light emitted, absorbed or scattered by the collected
magnetically labeled targets.
[0030] The complete system comprises optical tracking beam analysis
components similar to those employed for reading compact discs
known in the audio and data storage arts (see PCT/US02/04124).
Briefly, a pair of laser diodes generates parallel beams of light.
One beam is employed by the analysis system (not shown) for
locating and tracking lines of the target entities. The other beam
is used for detecting the presence of collected target entities
adjacent to a located line. Relative motion between the cartridge
and the optical elements of the analysis system is provided by a
mechanical translation unit (not shown). Coordination of the
functions of the analysis system is provided by a microprocessor
(not shown). The tracking beam, which is reflected by dichroic
mirror through the aperture is focused upon the upper surface of
the cartridge by an objective lens. The dichroic mirror 7 through
the dichroic lens and the objective lens reflects the detecting
beam.
[0031] Light reflected by the tracking lines and the target
entities will be transmitted through dichroic mirrors and toward a
photo detector (not shown). The detector generates a data signal,
which is fed to the microprocessor for the unit, as described more
fully in the above-mentioned U.S. Pat. No. 5,985,153, to control
the translation of the unit and process the data provided by the
detector.
[0032] The improved cartridge 21 may also be used in other
detecting apparatus such as a microscope, as described in the
above-mentioned U.S. Pat. No. 6,013,532, in which the stage is
designed to receive the receptacles 20 so as to position the
surface of the cartridge in the light path of the microscope. As
noted above, the orientation of the test chamber may be horizontal,
vertical or at any angle determined by the instrumentation of the
detecting apparatus.
[0033] As shown in the orientation of FIG. 1, the improved
cartridge 21 has a domed body portion 51 having outwardly
projecting glides 52 and 53 on opposite sides thereof. While
holding the cartridge by the grips 37 38, the glides 52 and 53 are
designed to slide into guide ways 54 and 55 in the receptacle so
that the domed body portion of the cartridge underlies the lower
surfaces of the poles 22 and 23. Intermediate between the guide
ways 54 and 55, the receptacle has a slot 56 providing an optical
path through the bottom of the receptacle. The optical path
registers with the longitudinal centerline of the cartridge when
the cartridge is inserted into position within receptacle 20.
[0034] FIG. 2 shows the cartridge 21 in front view embodying the
present invention and the associated improvements with its stopper
in place to illustrate the engagement of the stopper with the body
of the cartridge. The stopper is shown with plug 74 sealingly
engage. With the stopper fully inserted, the plug 74 closes the
proximal end of the vestibule. The stopper has an improved handhold
75 and an improved locking mechanism composed of two flexible walls
76, 76. The flexible walls 76, 76 flank the plug 74 and engage
their respective keeper elements 77, 77 also improved and located
in the handle portion 61 of the cartridge. The improved keeper
elements are supported at the top of the handle portion and
laterally along the sides of the keeper elements. This provides
extra rigid support when engaged as shown.
[0035] FIG. 3 shows the cartridge 21 in front view embodying the
present invention and the associated improvements with its stopper
removed to illustrate the difference when not engaged with the body
of the cartridge
[0036] The improved cartridge is formed from a non-magnetic inert
material, such as polycarbonate, polystyrene or acrylic with no
fluorescent additives and is formed to provide a rigid chamber,
which may be manipulated into and out of the optical path of the
optical analysis system. A sectional view with the stopper removed
shows the cartridge with flanking grips 37, 38 and a centrally
located flat land surface 62 formed from optically clear material
such as glass and affixed at the top of the dome 51 (FIG. 4A).
[0037] A procedure for affixing the optically clear land surface 62
to the cartridge is incorporated into the embodiment to provide
better adhesion (see FIG. 4), a more consistent orientation of the
land surface 62 with respect to the viewing aperture, but most
importantly less interference with optical analysis due to excess
adhesive in the chamber area. The procedure allows for a more even
and controlled application of the adhesive along the interface
between the land surface 62 and the top of the non-magnetically
inert dome 51. More specifically, the improved affixation prevents
the adhesive from spreading in both lateral directions by forcing
adhesive away from the chamber area.
[0038] Basically, the improvement is in the geometry of an adhesive
trough 12, which is designed to channel the adhesive away from the
chamber area when the flat land surface is attached (FIG. 4B). The
molded inert material of the cartridge dome is shaped as a small
shelf 15 at the edge to form the contact area with the flat land
surface 62. A small trough, filled with adhesive, runs along the
edge. The trough spans the entire contact area so that when the
flat land surface is placed on the edge, contact is made with the
adhesive. The adhesive is allowed to wick down the trough and
across the contact area. This area is then exposed to UV light,
heat cured, or treated by any means to securely bond the edge to
the land surface. The preferred embodiment is to use a UV light
adhesive to bond 0.5 mm thick glass cut to tight tolerances with
molded plastic. The molded plastic must be non-fluorescent, rigid,
optically clear, and non-reactive with the sample. Typical examples
are polycarbonate or polystyrene.
[0039] The land surface 62 is optically clear and permanently
affixed to the cartridge. Thus when positioned in the receptacle
20, the test chamber 63 is aligned with the aperture 56 of the
receptacle along the light path of the detecting apparatus in which
receptacle 20 is mounted. This provides for an optimum analytical
viewing surface.
[0040] The test chamber 63 is closed at the distal end remote from
the handle portion 61 and has an inlet opening 65 at the proximal
end adjacent the grips 37, 38 (FIG. 5A). The inlet 65 is positioned
in the center of the end wall of the test chamber 63 at the
proximal end so that when the cartridge is disposed vertically for
filling the inlet opening 65 is at the uppermost part of the
chamber 63. The body of the cartridge provides a vestibule chamber
66 having an enlarged mouth 67 at its entrance end. The vestibule
chamber 66 communicates with the test chamber 63 through the inlet
opening 65. Between the mouth 67 and the inlet 65, the vestibule 66
provides an overflow reservoir, as described more fully
hereinafter.
[0041] The test chamber 63 is adapted to be closed by the plunger
71 of an improved stopper having a probe 72 adapted for sealing
through an engagement with the inlet 65 of the test chamber 63.
Rearwardly of the probe 72, the stopper has a ribbed stem 73. The
ribbed stem terminates into a plug 74, which is adapted to
sealingly engage in the mouth 67 as the stopper is fully inserted
through the vestibule 66. When fully inserted, the plug 74 closes
the proximal end of the vestibule 66. Beyond the plug 74, the
stopper has an improved handhold 75 and an improved locking
mechanism composed of two flexible walls 76, 76. The flexible walls
76, 76 flank the plug 74 and engage their respective keeper
elements 77, 77 also improved and located in the handle portion 61
of the cartridge. The improved keeper elements are supported at the
top of the handle portion and laterally along the sides of the
keeper elements. This provides extra rigid support when engaged.
When the flexible walls of the stopper 76, 76 are engaged, they are
compressed as they are pushed by the improved keeper elements 77,
77, but then snap outwardly when finally in place.
[0042] The improved cartridge has a handle portion 61 with
associated grips enabling the insertion and removal of the
cartridge into and out from the receptacle. The handle portion 61
has also been improved by flaring the side grips 37, 38 located
orthogonal to the first face. The grip area is made to flare away
from the radial axis of the cartridge. The handle portion has an
arch-like extension on a first face. The first face is located on
the domed side of the body. This face includes the domed body
portion 51 with projecting guides 52 and 53 of the cartridge and
the first face of the hand portion 61, defined along an upper edge
of improved grips 37, 38, a curved upper edge of the arch-like
extension 39, and the upper edge 40 which forms a border above the
domed body portion 51 of the cartridge. A second face of the handle
is opposite the dome body, and contains an inner-framed structure
bounded along the radial axis of the cartridge by the two keeper
elements 77, 77 and along a longitudinal axis by the uppermost
portion of the handle and the enlarged mouth 67 of the vestibule.
Changes to both faces provide a more secure lock for the stopper
when engaged in position, and a much-improved rigid support for
cartridge manipulation.
[0043] The projecting part of the stopper including the probe 72
and the plug 74 comprise an elastomeric material such as a
thermoplastic elastomer (DYNAFLEX.RTM.), or other elastomeric
material capable of forming seals with the inlet 65 and the mouth
67, respectively. The elastomeric material must also be
non-fluorescent and non-reactive with the sample. The durometer of
the elastomeric material is in the range of about 60 to 100 with a
more preferred range of about 80 to 90 and the most preferred about
90. The handhold 75 of the stopper and the flexible walls 76, 76
are formed of the same elastomer as the probe and plug, thus making
the entire stopper composed of a single elastomer. As with the
parental cartridge/stopper, there is little ability to twist the
stopper handhold 75 about its axis, especially after the flexible
walls are securely locked into place. To release their engagement
with the keepers 77, 77, a window within the framed area of the
cartridge handhold 61 allows access for manual compression of the
flexible walls and reversal of the engagement. Overall, this single
elastomer design provides for a lower cost cartridge/stopper
assembly.
[0044] As shown in FIGS. 4C, the cartridge is disposed with its
longitudinal axis horizontal so that the flat land area 62 of the
test chamber 63 is disposed within the field of observation of the
detection equipment. When filling the test chamber 63, the
cartridge is disposed with its longitudinal axis upright with the
vestibule 66 disposed above the test chamber 63.
[0045] As shown in FIGS. 5A to 5C, a test liquid is introduced into
the test chamber 63 along with any associated buffer solution. The
buffer solution has a density which is less than or equal to the
test liquid so that there is a liquid interface provided between
the two solutions. The volume of the buffer solution is sufficient
to completely fill the test chamber 63. The filling operation
excludes air from the test chamber 63, and any air bubbles
remaining in the buffer solution will gravitate upwardly through
the inlet 65 into the vestibule 66.
[0046] The construction and arrangement of the chamber insures that
air bubbles are excluded from the test chamber and pressure
build-up in the unit is avoided. As shown in FIGS. 5A to C, when
the stopper 60 is inserted into the vestibule, a projecting portion
containing the probe 72 displaces the buffer solution as it enters
the established fill line and causes the surface of the buffer
solution to rise within the vestibule until the probe 72 contacts
the inlet 65. As shown, the inlet 65 has a flared mouth 88 and a
cylindrical channel 89 below the flared mouth (FIG. 5B). At this
point, the surface of the buffer solution is shifted upwardly to an
elevated fill line. Further movement of the stopper downwardly
causes the tip of the probe 72 to enter the channel 89 of the inlet
65. When the probe 72 engages the cylindrical channel 89, the probe
affects a first seal, closing communication between the test
chamber 89 and the vestibule 66. Further penetration of the probe
72 into the cylindrical portion of the cylindrical channel 89 of
the inlet 65 perfects the seal (FIG. 5C). Because the tip of the
probe 72 closes the cylindrical channel 89, and, in the present
instance, the internal diameter of the channel 89 of the inlet 65
is less than the internal dimensions of the chamber 63 so that the
volume of buffer solution in the channel is minimal, and the
engagement of the probe 72 into the channel 89 when effecting the
first seal does not significantly increase the pressure within the
test chamber 63. The vestibule remains open at the top until the
plug 74 enters the mouth 67, allowing the vestibule to remain at
ambient pressure.
[0047] The design of the present invention may be used for any
analysis chamber, but it has been specifically created for analysis
chambers for testing extremely small samples having a volume of
less than 1 ml. In the illustrated embodiment, referring to FIG.
4B, the width of the chamber 63 below the land area 62 is
approximately 3 mm and the depth is approximately 4 mm, providing a
cross-sectional area in the range of 10 to 14 square millimeters.
The length along the longitudinal axis is approximately 30 mm. The
volume of the chamber 63 should be in the range between 22 ul and
675 ul, preferably at least 315 ul. The diameter of the inlet 65 is
in the range between 0.0381 mm and 3.18 mm, and preferably is 2.35
mm, providing a flow area of approximately 10 square millimeters.
Beyond the inlet 65, the vestibule flares out, in this case to a
diameter of 4.23 mm, and extends approximately 14 mm to the mouth
67, which, in this case, has a width of 6.3 mm. With the plug fully
inserted, the volume of the vestibule 66 is preferably at least 95
ul. The width of the test chamber at the upper wall is slightly
more than the diameter of the channel 89 of the inlet 656. Although
not shown in the figures, the corners around the perimeter of the
upper wall are broken or beveled, so as to avoid entrapment of any
air bubbles gravitating upwardly through the chamber 63. The bevel
is preferably at an angle of between 2.degree. and 30.degree.
relative to the longitudinal axis of the chamber 63 and the inlet
65.
[0048] Further displacement of the stopper 60 allows the plug 74 at
the proximal end of the stem 73 to engage in the enlarged mouth 67
of the vestibule and affect a second seal closing the upper end of
the vestibule. As shown in FIGS. 6 and 7, the plug 74 is a
rectangular block to mate with the enlarged mouth 67, which is in
the form of a socket having a complementary rectangular form. The
block 74 is of the same plastic material as the probe 72 having
sufficient resiliency to effect a good seal with the enlarged mouth
67 when engaged as shown in FIG. 5C. The displacement of the plug
74 in the enlarged mouth 67 does not substantially increase the air
pressure above the fill line 87.
[0049] The distance between the top of the cylindrical channel 89
of the inlet 65 and the bottom of the socket forming the enlarged
mouth 67 is less than the distance between the tip of the probe 72
and the bottom of the plug 74 so that there is assurance that the
probe enters into the channel 89 before the plug 74 seats against
the bottom of the socket. This arrangement insures avoidance of any
substantial pressure build-up in the vestibule 66. It is noted that
the stem 73 has ribs 91 spaced circumferentially there around so
that the space between the ribs provides an adequate space to
accommodate the buffer solution displaced during the penetration of
the probe into the cylindrical portion 89 of the inlet.
[0050] With the flexible walls engaging the keeper element 77 to
keep the stopper in place, air is confined within the vestibule 66
between the first and second seals, and the cartridge may be
manipulated without fear of air bubbles or the like interfering
with the optical analysis of the liquid in the test chamber 63.
After being filled and capped, the cartridge may be reoriented so
that its longitudinal axis is horizontal for analysis in the
detecting apparatus, as described above and illustrated in FIGS. 1
to 4, since the test chamber 63 is completely filled with liquid,
it may be manipulated into other orientations, as may be required
by the detecting apparatus chosen by the analyst. Any buffer
solution, which is in contact with the test liquid is retained
within the cartridge, either in the test chamber 63 or within the
vestibule 66, and there is little danger of loss of any significant
part of the test liquid. The buffer solution, which overlies the
test liquid in the cartridge during the filling operation, assures
minimal exposure of the test liquid to air and a diminished risk of
deterioration or contamination of the test liquid.
[0051] The contents of the articles, patents, and patents
applications and all other documents and electronically available
information mentioned or cited herein, are hereby incorporated by
reference in their entirety to the same extent as if each
individual publication was specifically and individually indicated
to be incorporated by reference. Applicant reserves the right to
physically incorporate into this application any and all materials
and information from any such articles, patents, patent
applications, or other physical and electronic documents.
[0052] While particular embodiments of the present invention have
been herein illustrated and described, it is not intended to limit
the invention to such disclosure, and many changes and
modifications can be envisioned therein that may be made within the
scope of the following claims.
* * * * *