U.S. patent application number 17/727262 was filed with the patent office on 2022-08-04 for system and method for confining reagents within a fluidic device.
The applicant listed for this patent is Integrated Nano-Technologies, Inc.. Invention is credited to Dennis M. CONNOLLY, Mark J. SMITH, Nathaniel E. WESCOTT.
Application Number | 20220241790 17/727262 |
Document ID | / |
Family ID | 1000006276877 |
Filed Date | 2022-08-04 |
United States Patent
Application |
20220241790 |
Kind Code |
A1 |
WESCOTT; Nathaniel E. ; et
al. |
August 4, 2022 |
SYSTEM AND METHOD FOR CONFINING REAGENTS WITHIN A FLUIDIC
DEVICE
Abstract
A method for inserting and retaining a reagent within a
disposable cartridge of a diagnostic assay system. The method
includes the steps of: (i) drying a reagent in combination with a
carrier, and (ii) inserting the carrier, with the dried reagent,
into an open end of one of the assay chambers, wherein the carrier
facilitates insertion of the pellet into a chamber without contact
by an operator.
Inventors: |
WESCOTT; Nathaniel E.; (West
Henrietta, NY) ; CONNOLLY; Dennis M.; (Rochester,
NY) ; SMITH; Mark J.; (Rochester, NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Integrated Nano-Technologies, Inc. |
Henrietta |
NY |
US |
|
|
Family ID: |
1000006276877 |
Appl. No.: |
17/727262 |
Filed: |
April 22, 2022 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16306194 |
Nov 30, 2018 |
11311885 |
|
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PCT/US2017/035671 |
Jun 2, 2017 |
|
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17727262 |
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62344537 |
Jun 2, 2016 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B01L 3/527 20130101;
B01L 2300/047 20130101; B01L 2300/0832 20130101; B01L 2300/042
20130101; B01L 2300/0681 20130101; B01L 3/502 20130101; B01L
2200/16 20130101; B01L 2200/12 20130101; B01L 2300/06 20130101 |
International
Class: |
B01L 3/00 20060101
B01L003/00 |
Claims
1. A method for retaining a reagent within a disposable cartridge
of a diagnostic assay system, the disposable cartridge having at
least one assay chamber for holding and mixing assay fluids,
comprising the steps of: drying a reagent in combination with a
carrier; and inserting the carrier, with the dried reagent, into an
open end of one of the assay chambers, wherein the carrier
comprises a pod enclosing the dried reagent and having a by-pass
filter at one end to facilitate rehydration of the dried reagent
upon injection of an assay fluid into the assay chamber.
2. The method of claim 1, wherein the carrier comprises a cap
having an open end for receiving the dried reagent and a closed end
for enclosing the open end of the assay chamber.
3. The method of claim 2, wherein the diagnostic assay system
comprises a cartridge rotor that contains the at least one assay
chamber, the method further comprising: overturning the cartridge
rotor to facilitate insertion of the cap upwardly into the open end
of the assay chamber.
4. The method of claim 1, wherein the carrier comprises a
plug-spring having a spring element with the dried reagent attached
to one end of the spring element and configured to: (i) plug the
open end of the assay chamber and (ii) bias the dried reagent
downwardly into the assay chamber.
5. The method of claim 4, wherein the spring element is a coil
spring extending along an elongate axis of the chamber.
6. A method for retaining a reagent within a disposable cartridge
of a diagnostic assay system, the disposable cartridge having at
least one assay chamber for holding and mixing assay fluids,
comprising the steps of: forming a pellet of dried reagent;
combining the dried pellet with a carrier configured to be received
within one of the assay chambers of the disposable cartridge; and
inserting the carrier, with the dried pellet, into an open end of
one of the assay chambers, wherein the carrier comprises a pod
enclosing the dried pellet and having a by-pass filter at one end
to facilitate rehydration of the dried pellet upon injection of an
assay fluid into the assay chamber.
7. The method of claim 6, wherein the carrier comprises a cap
having an open end for receiving the dried pellet and a closed end
for enclosing the open end of the assay chamber.
8. The method of claim 7, wherein the diagnostic assay system
comprises a cartridge rotor that contains the at least one assay
chamber, the method further comprising: overturning the cartridge
rotor to facilitate insertion of the cap upwardly into the open end
of the assay chamber.
9. The method of claim 6, wherein the carrier comprises a
plug-spring having a spring element with the dried pellet attached
to one end of the spring element and configured to: (i) plug the
open end of the assay chamber and (ii) bias the dried pellet
downwardly into the assay chamber.
10. The method of claim 9, wherein the spring element is a coil
spring extending along an elongate axis of the chamber.
11. A disposable cartridge comprising: a carrier disposed in at
least one assay chamber of the disposable cartridge and configured
to secure a dehydrated reagent, the carrier being configured to
facilitate rehydration of the dehydrated reagent upon the
introduction of an assay fluid into the assay chamber, wherein the
carrier comprises a pod enclosing the dehydrated reagent and having
a by-pass filter at one end to facilitate rehydration of the
dehydrated reagent upon injection of the assay fluid into the assay
chamber.
12. The disposable cartridge of claim 11, wherein the carrier
comprises a cap having an open end for receiving the dehydrated
reagent and a closed end for enclosing the open end of the assay
chamber immediately prior to use.
13. The disposable cartridge of claim 11, wherein the carrier
comprises a spring element projecting from a plug configured to be
retained within a rim of an open-ended assay chamber, the spring
element being configured to bias the dehydrated reagent downwardly
into the assay chamber.
14. The disposable cartridge of claim 12, wherein, after loading
the cap with the dehydrated reagent, the cap is filled with an
inert gas and includes a detachable cover to contain the inert gas
within the cap to reduce oxidation of the dehydrated reagent.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. application Ser.
No. 16/306,194, filed Nov. 30, 2018, which is a National Stage
Entry of International Application No. PCT/US2017/035671, filed
Jun. 2, 2017, which claims priority to U.S. Provisional Application
No. 62/344,537, filed Jun. 2, 2016, which are hereby incorporated
herein in their entireties by reference.
[0002] This application also relates to International Application
No. PCT/US2017/032904, filed May 16, 2017, entitled "Flow Control
System for Diagnostic Assay System," which claims priority to U.S.
Provisional Application No. 62/337,446, filed May 17, 2016,
entitled "Multi-Chamber Rotating Valve and Cartridge."
Additionally, this application also relates to U.S. application
Ser. No. 15/157,584, filed May 18, 2016, entitled "Method and
System for Sample Preparation," which is a continuation of U.S.
application Ser. No. 14/056,543, filed Oct. 17, 2013, now U.S. Pat.
No. 9,347,086, which claims priority to U.S. Provisional
Application No. 61/715,003, filed Oct. 17, 2012, which is a
continuation-in-part of U.S. application Ser. No. 12/785,864, filed
May 24, 2010, now U.S. Pat. No. 8,663,918, which claims priority to
U.S. Provisional Application No. 61/180,494, filed May 22, 2009,
and which is also a continuation-in-part of U.S. application Ser.
No. 12/754,205, filed Apr. 5, 2010, now U.S. Pat. No. 8,716,006,
which claims priority to U.S. Provisional Application No.
61/158,519, filed Apr. 3, 2009. The contents of the aforementioned
applications are hereby incorporated by reference in their
entirety.
BACKGROUND
Field
[0003] The present disclosure relates to a disposable cartridge for
a portable diagnostic assay device, and more particularly, to a
system and method for producing and confining dried reagents in one
of the chambers of the disposable cartridge for subsequent
rehydration during assay testing.
Background
[0004] Fluid analysis of biological samples such as blood and food
samples for assay testing generally requires a series of process
steps. These steps generally require that particular fluids contact
a reaction area at different times and in varying secession.
Furthermore, each fluid may require different pre-treatment prior
to contacting the reaction area such as chemical, optical, thermal,
mechanical, magnetic or acoustical pre-treatment. A single fluid
sample may be subjected to a variety of steps prior to contact with
a reaction area such as heating or ultrasonic processing. As the
number of fluids and pre-treatment steps increase, the fluid
delivery system becomes more complex.
[0005] One of the more recent developments in the field of
diagnostic testing relates to a portable diagnostic assay device
capable of performing a variety of common and complex laboratory
procedures without the requirement for a staff of highly-skilled
technicians to perform these procedures in a costly laboratory
environment/setting. The portable diagnostic assay device and
related diagnostic cartridges are disclosed in a portfolio of
issued and pending U.S. and foreign patents/patent applications
assigned to Integrated Nano-Technologies located in the town of
Henrietta, state of New York, USA. The portable diagnostic assay
device comprises a small base unit, i.e., generally smaller than a
standard briefcase, for accepting one of many distinct, dedicated,
and disposable cartridges prepared for conducting a single assay
test. For example, the disposable cartridges may be prepared for
testing blood borne diseases, food borne bacteria, and/or
animal/insect carrying bacteria and viruses.
[0006] The diagnostic cartridges comprise a plurality of chambers
each containing a reagent used in the assay test, e.g., PCR
primers, enzymes and certain chemical compounds. To maximize shelf
life and reliability, these reagents are typically
dehydrated/lyophilized and sealed within the chambers of the
diagnostic cartridge. During storage, handling and transport, the
dried reagents can break apart such that a film of powder coats the
internal chamber, as well as the ports and channels leading to and
from the chamber. Inasmuch as each gram of reagent is needed to
ensure reliable/consistent test results, it will be appreciated
that any unused or inaccessible portion of reagent, e.g., a portion
which remains logged in a comer of a chamber or disposed in a vent
port, can adversely impact the test results.
[0007] There is, therefore, a need for a system and method for
confining a reagent in a disposable cartridge for a portable
diagnostic assay device which facilitates complete admixture of the
confined reagent with a solvent, fluid reagent or other fluid assay
chemical injected into, or withdrawn from, an assay chamber.
SUMMARY
[0008] In one embodiment, a method is provided for retaining a
reagent within a disposable cartridge of a diagnostic assay system.
The method includes the steps of: (i) drying a reagent within a
carrier configured to be received within an open end of one of the
assay chambers, and (ii) inserting the carrier, including the
pellet of dried reagent, into an open end of the assay chamber,
wherein the carrier facilitates insertion of the pellet into a
chamber without contact by an operator.
[0009] In another embodiment, a method comprises (i) drying a
reagent in combination with a carrier configured to be received
within an open end of one of the assay chambers, and (ii) the
carrier, including the dried reagent, is inserted into an open end
of the assay chamber, wherein the carrier facilitates insertion of
the pellet into a chamber without contact by an operator.
[0010] In another embodiment, the method comprises the steps of:
(i) producing a scaffold structure having a geometric shape
approximating the shape of a portion of the least one assay
chamber, (ii) mixing a reagent, a binder and a liquid solvent,
(iii) impregnating the scaffold structure with the liquid
reagent-binder, and (iv) drying the liquid reagent-binder to remove
the solvent thereby producing a dried reagent having the geometric
shape corresponding to the shape of the assay chamber.
[0011] In yet another embodiment, a disposable cartridge is
provided comprising: (i) a cartridge body defining a syringe barrel
having a barrel port operative to inject and withdraw assay fluids
in response to displacement of a syringe plunger; (ii) a cartridge
rotor comprising: a plurality of assay chambers rotatable about an
axis and mounted for rotation to the cartridge body, the cartridge
rotor defining a port disposed in fluid communication with at least
one of the assay chambers and rotated into alignment with the
barrel port of the syringe barrel, and (iii) a carrier disposed in
one of the assay chambers, configured to secure a dehydrated
reagent, and facilitating rehydration of the reagent upon the
introduction of a fluid solvent into the assay chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The present disclosure is disclosed with reference to the
accompanying drawings, wherein:
[0013] FIG. 1 is a perspective view of a portable diagnostic assay
system operative to accept one of a plurality of disposable
cartridges configured to test samples of collected
blood/food/biological materials.
[0014] FIG. 2 is an exploded perspective view of one of the
disposable cartridges configured to test the blood/food/biological
materials.
[0015] FIG. 3 is a top view of the one of the disposable cartridges
illustrating a variety of assay chambers including a central assay
chamber for receiving the blood/food/biological material and at
least one other chamber containing an assay chemical suitable to
breakdown the blood/food/biological material to detect a particular
attribute thereof.
[0016] FIG. 4 is a bottom view of the disposable cartridge shown in
FIG. 3 illustrating a variety of channels operative to move at
least a portion of the assay material from one chamber to another
the purpose of performing multiple operations on the sample.
[0017] FIG. 5 is a broken-away, cross-sectional, schematic view of
an assay chamber being prepared for accepting a
dehydrated/lyophilized assay chemical in a sump region of one of
the assay chambers.
[0018] FIGS. 6-10 depict schematic perspective views of various
method steps which may be necessary to prepare an assay chamber for
a dissolvable assay material, pellet, sphere, pill or container
including the steps of: (i) forming a support scaffold in a
geometric shape which is supported within and captured by a portion
of an assay chamber (FIG. 6), (ii) inserting the support scaffold
in a fluid container approximating the geometric shape of the assay
chamber (FIG. 7), (iii) loading the support scaffold with an assay
material which has been dissolved in a flowable solvent (FIG. 8),
(iv) dehydration or lyophillization of the assay material in
combination with the support scaffold (FIG. 9), and, (v)
transferring the support scaffold (loaded with assay material) into
the assay chamber of the disposable cartridge (see FIG. 10).
[0019] FIG. 11 depicts an isolated perspective view of another
embodiment of the disclosure wherein an assay chemical is prepared
for handling and transport within a carrier pod or container having
an end suitable for receiving and mixing the assay chemicals of one
chamber with the assay chemicals of another chamber.
[0020] FIG. 12 depicts the carrier pod having a screened- or
filtered-end to allow mixture of the assay chemicals/fluids when
the filtered-end of the carrier pod is placed face down in the
assay chamber for receipt of injected assay chemicals by a syringe
barrel of the disposable cartridge.
[0021] FIG. 13 depicts an isolated perspective view of a cap
holding a pellet of dried reagent for being received within an
assay chamber of the disposable cartridge.
[0022] FIG. 14 depicts an isolated perspective view of an
over-turned cartridge rotor for receiving the pellet of dried
reagent depicted in FIG. 13.
[0023] FIG. 15 depicts a broken-away, sectional view of the
cartridge rotor wherein an assay chemical, in the form of a pellet,
sphere, pill or other dissolvable shape, is spring-biased
downwardly, toward a portion of the assay chamber which fills with
an assay fluid during one of the mixing steps.
[0024] Corresponding reference characters indicate corresponding
parts throughout the several views. The examples set out herein
illustrate several embodiments of the disclosure but should not be
construed as limiting the scope of the disclosure in any
manner.
DETAILED DESCRIPTION
[0025] A disposable cartridge is described for use in a
portable/automated assay system such as that described in
commonly-owned, co-pending U.S. application Ser. No. 15/157,584,
filed May 18, 2016, entitled "Method and System for Sample
Preparation," which is hereby included by reference in its
entirety. While the principal utility for the disposable cartridge
includes DNA testing, the disposable cartridge may be used in be
used to detect any of a variety of diseases which may be found in
either a blood, food or biological specimen. For example, blood
diagnostic cartridges may be dedicated cartridges useful for
detecting hepatitis, autoimmune deficiency syndrome (AIDS/HIV),
diabetes, leukemia, graves, lupus, multiple myeloma, etc., just
naming a small fraction of the various blood borne diseases that
the portable/automated assay system may be configured to detect.
Food diagnostic cartridges may be used to detect salmonella,
e-coli, staphylococcus aureus or dysentery. Insect or animal borne
diseases include malaria, encephalitis and the West Nile virus.
[0026] More specifically, and referring to FIGS. 1 and 2, a
portable assay system 10 receives any one of a variety of
disposable assay cartridges 20, each selectively configured for
detecting a particular attribute of a fluid sample, each attribute
potentially providing a marker for a blood, food or biological
(animal borne) disease. The portable assay system 10 includes one
or more linear and rotary actuators operative to move fluids into,
and out of, various compartments or chambers of the disposable
assay cartridge 20 for the purpose of identifying or detecting a
fluid attribute. More specifically, a signal processor 14, i.e., a
PC board, controls a rotary actuator (not shown) of the portable
assay system 10 so as to align one of a variety of ports 18P,
disposed about a cylindrical rotor 18, with a syringe barrel 22B of
a stationary cartridge body 22. The processor 14 controls a linear
actuator 24, to displace a plunger shaft (not shown) so as to
develop pressure i.e., positive or negative (vacuum) in the syringe
barrel 22. That is, the plunger shaft displaces an elastomer
plunger 28 within the syringe 22 to move and or admix fluids
contained in one or more of the chambers 30, 32.
[0027] The disposable cartridge 20 provides an automated process
for preparing the fluid sample for analysis and/or performing the
fluid sample analysis. The sample preparation process allows for
disruption of cells, sizing of DNA and RNA, and
concentration/clean-up of the material for analysis. More
specifically, the sample preparation process of the instant
disclosure prepares fragments of DNA and RNA in a size range of
between about 100 and 10,000 base pairs. The chambers can be used
to deliver the reagents necessary for end-repair and kinase
treatment. Enzymes may be stored dry and rehydrated in the
disposable cartridge, or added to the disposable cartridge, just
prior to use. The use of a rotary actuator allows for a single
plunger to draw and dispense fluid samples from a single rotary
device without the need for a complex system of test tubes, carrier
probes, and valves to move in unison or open/close at precise
times. This greatly reduces potential for leaks and failure of the
device compared to conventional systems. It will also be
appreciated that the system greatly diminishes the potential for
human error.
[0028] In FIGS. 2, 3, and 4, the cylindrical rotor 18 includes a
central chamber 30 and a plurality of assay chambers 32, 34
surrounded, and separated by, one or more radial or
circumferential, or planar walls 18E, 18W, and 40F, respectfully.
In the described embodiment, the central chamber 30 receives the
fluid sample while the surrounding chambers 32, 34 may contain a
premeasured assay chemical or reagent for the purpose of detecting
an attribute of the fluid sample. The chemical or reagents may be
initially dry and rehydrated immediately prior to conducting a
test. Some of the chambers 32, 34 may be open to allow the
introduction of an assay chemical while an assay procedure is
underway or in-process. The chambers 30, 32, 34, 36, 38 are
disposed in fluid communication, e.g., from one of the ports 18P,
46 to one of the chambers 30, 32, 34, by channels 40, 42 molded
along a bottom panel 44, i.e., along an underside surface 44S of
the rotor 18.
[0029] During development of the disposable cartridge and
diagnostic assay system, the inventors determined that to maximize
shelf life and reliability, reagents such as PCR primers, enzymes
and certain chemical compounds must be dehydrated or lyophilized.
They also discovered, however, that such dehydration or
lyophillization caused damage to the delicate/dried assay chemicals
and reduced PCR yield. That is, during loading and handling, the
dried assay chemicals tended to break-apart causing a powdered
residue to lodge in comers, inlet and outlet ports or other areas
where rehydration fluid could not reach. Inasmuch as PCR reactions
are logarithmic in scale as a function of mix accuracy, even small
deviations can result in poor yield. To address these deficiencies,
the inventors discovered a variety of improvements relating to the
loading methodology of the reagents to significantly improve the
subsequent yield.
[0030] In one embodiment of the disclosure, and referring to FIG.
5, a method is provided for confining a dried reagent within the
disposable cartridge 20 of the diagnostic assay system 10. In this
embodiment, a scaffolding structure 54 provides a stabilizing
matrix or reinforcement for a dehydrated or lyophilized assay
chemical. More specifically, the scaffolding structure 54 is formed
in the shape of a portion of the assay chamber 32 which limits or
inhibits the lateral motion of the dehydrated or lyophilized assay
chemical. The scaffolding structure 54 comprises a matrix of wire,
netting or opened-celled foam material and is formed in the shape
of a lower sump region/portion 56 of the assay chamber 32. In the
described embodiment, the scaffolding structure 54 forms a
conically-shaped depression in the bottom portion or panel 44 of
the disposable cartridge 20. In the context used herein, a sump
region 56 is any low point in a cavity wherein a fluid collects
under the influence of gravity.
[0031] In a first step of the method, the scaffolding structure 54
is shaped in the form of a cylindrical disc or pellet and inserted
into the sump region 56 of the assay chamber 32. Next, an assay
chemical, a binder and/or a liquid solvent is combined to produce a
flowable, liquid reagent-binder 58. Finally, the scaffold structure
54 is impregnated with the liquid reagent-binder 58 and dried,
i.e., via dehydration or lyophillization, to provide shape, form
and strength to the dried reagent 60. Preferably, the dried
reagent-binder 60 is placed within a portion of the assay chamber
32 which limits the lateral motion of the dried reagent-binder such
as within the conically-shaped sump region 56 of the assay chamber
32. Alternatively, the dried reagent 60 may bond to the lower panel
44 of the assay chamber 32 such that the reagent 60 remains stable,
i.e., does not move or displace, while the disposable cartridge is
shipped during transport.
[0032] During use, liquid solvents and/or other liquid assay
chemicals are injected into the assay chamber 32 by the syringe
barrel 22B of the cartridge body 22. The assay fluid flows into the
sump region 56 of the assay chamber 32, inasmuch as the sump region
56 is a low-point in the chamber 32. As a consequence, the assay
fluid rehydrates the dried reagent 60 supported by the scaffolding
structure 54.
[0033] In another embodiment of the method, the scaffolding
structure 54, once again, is formed in the shape of a portion of
the assay chamber 32. However, rather than being formed in a sump
region of the assay chamber 32, a mold or mold container 62 is
provided to form, impregnate and transfer the dried reagent 60 into
the bottom or sump region 56 of the assay chamber 32. More
specifically, FIG. 6 depicts the scaffolding structure 60 being
disposed into a mold cavity 64 of the container 62. FIG. 7 depicts
a liquid mixture 58 of the reagent, binder and liquid solvent as it
is poured into the mold cavity 64. In FIG. 8, the scaffolding
structure 60 is impregnated with the liquid mixture 58 while FIG. 9
depicts the dehydration or lyophillization of the impregnated
structure 60. Once the impregnated structure 60 is dried, the mold
62 is overturned in FIG. 10 to empty the dried reagent 60 from the
mold cavity 64. In this embodiment, the reagent 60 is transferred,
placed and/or bonded into the base or sump region 56 of the assay
chamber 32. Once again, assay fluids injected into the chamber 32
function to rehydrate the dried reagent 60 of the scaffolding
structure 54.
[0034] In yet another embodiments, a dried reagent 70 may or may
not be reinforced by a scaffolding structure 54. In these
embodiments, the dried reagent 70 may simply comprise a reagent
bound together by a binding agent, i.e., a glucose binder.
Furthermore, a carrier 72 secures or holds the dried reagent in
combination with the assay chamber 32 while mitigating, limiting or
otherwise minimizing the amount of handling, interaction, or
intervention by an operator. As will be discussed in the
embodiments disclosed in FIGS. 11 through 15, the carrier 72 may
comprise: (i) an enclosed pod 74 having a fluid by-pass filter at
one end for rehydrating a pellet of dried reagent 70, (ii) a cap 76
defining a cavity having an open end for accepting a pellet 70, or
a removable cover to open and close the open end, or, (iii) a
plug-spring 78 having a spring element 90 configured to bias a
pellet 70 of dried reagent downwardly into the assay chamber
32.
[0035] In FIGS. 11 and 12, the pod 74 encloses the pellet 70 and
includes a by-pass filter 80 at one end to facilitate rehydration
of the dried reagent, i.e., the dried pellet 70, upon injection of
an assay fluid XX into the assay chamber 32. In the described
embodiment, the pod 74 may include a tubular sleeve 82 closed at
each of its ends 80, 84 to retain the pellet 70 within a relatively
small confinement area or volume. The pellet 70 may or may not be
reinforced by a scaffolding structure and the tubular sleeve 82 may
or may not be dissolvable by the assay fluid XX. Furthermore, the
pellet 70 of dried reagent may be formed while in the tubular
sleeve 82 or formed externally of the sleeve 82. That is, a mixture
of reagent, binder and a solvent may be loaded into the carrier 72
and dehydrated, lyophilized or freeze- dried while in the tubular
sleeve of the pod 74.
[0036] In the described embodiment, the by-pass filter 80 may be
detached from the tubular sleeve 82 to facilitate loading of a
pellet 70. Furthermore, to facilitate mixing with the assay fluid
XX, the by-pass filter 80 may be over-turned to face downwardly in
the assay chamber 32 such that assay fluid XX fill the pod 74
immediately upon injection of the assay fluid XX by the syringe
barrel 22B of the cartridge body.
[0037] In FIGS. 13 and 14, the cap 76 may include an open end 86
for receiving the pellet 70 of dried reagent and a closed end 88
for enclosing the open end of the assay chamber 32. In this
embodiment, the cartridge rotor 18 is overturned such that the
opening of the respective chamber 32 faces downwardly for receiving
an open end 86 of the cap 76. The cap 76 is press-fit into the open
end of the chamber 32 thereby enclosing the dried reagent, i.e.,
dried pellet 70, in the assay chamber 32. While this method does
not prevent the pellet 70 of reagent from moving in the chamber 32,
it limits contact by an operator with the dried pellet 70 prior to
loading within the assay chamber 32.
[0038] In another embodiment, the pellet 70 is loaded into the
tubular cap 76, filled with an inert gas such as helium or argon,
and closed by a detachable cover 86 to retain the pellet 70 along
with the gas. In this embodiment, the inert gas functions to reduce
oxidation of the dried pellet 70 in a time between initial
manufacture and use of the disposable cartridge 20. Consequently,
immediately prior to use, the operator removes the detachable cover
86 and press-fits the tubular cap 76 into the assay chamber 32 of
the cartridge rotor 18.
[0039] In yet another embodiment depicted in FIG. 15, a plug-spring
78 includes a pellet 70 attached to a spring element 90 which, in
tum, is mounted to an end plug 92. More specifically, in this
embodiment, the pellet 70 is spherically shaped, however, the
pellet 70 may be any shape which facilitates rehydration of the
dried reagent 70. The spring element 90 is disposed along the
elongate axis 32A of the chamber 32 and, in the described
embodiment, is a coil spring 90 having an end loop which cups or
circumscribes the spherical surface of the dried pellet 70.
Finally, the end plug 92 is cylindrical to engage the open end, or
rim 96, of the chamber 32. Consequently, the plug 92 secures the
spring element 90 and pellet 70 within the chamber 32, i.e.,
inhibiting displacement of the pellet 70 while the spring element
90 biases the pellet 70 downwardly, toward the base or bottom 44 of
the cartridge rotor 18. The pellet 70 may be biased toward the port
18P through which assay fluids are injected or withdrawn. While the
end plug 92 may be solid, it should be appreciated that the end
plug 92 may be porous to facilitate fluid flow into and out of the
chamber 32.
[0040] In summary, the various embodiments described hereinabove
provide a method and apparatus for securing a dried,
reinforced/unreinforced, reagent within an assay chamber 32 of a
disposable cartridge 20. Functionally, the methods minimize or
eliminate handling of the dried reagent 60, 70 by operators or
assembly personnel. The carrier pod 74 encloses the pellet 70 while
providing a fluid by-pass screen or filter to allow rehydration of
the dried reagent 70. The removable cover 86 of the cap 76 allows
the pellet 70 to be transported within a container 76 which may be
oxygen deprived (i.e., replaced by argon or helium) to prevent
oxidation in the time between manufacture and use. Finally, the
pellet 70 is protected from movement and vibrations induced during
transport of the disposable cartridge 20. As such, the propensity
for the pellet 70 to break-apart within the chamber 32 is
mitigated. That is, there is little or no opportunity for the
pellet 70 to crumble within the assay chamber 32 of the disposable
cartridge 20.
[0041] While the disclosure has been described with reference to
particular embodiments, it will be understood by those skilled in
the art that various changes may be made and equivalents may be
substituted for elements thereof without departing from the scope
of the disclosure. In addition, many modifications may be made to
adapt a particular situation or material to the teachings of the
disclosure without departing from the scope of the disclosure.
[0042] Therefore, it is intended that the disclosure not be limited
to the particular embodiments disclosed as the best mode
contemplated for carrying out this disclosure, but that the
disclosure will include all embodiments falling within the scope
and spirit of the appended claims.
* * * * *