Chemical apparatus and process disinfecting – deodorizing – preser – Control element responsive to a sensed operating condition
Reexamination Certificate
1998-03-31
2001-05-01
Jones, Deborah (Department: 1775)
Chemical apparatus and process disinfecting, deodorizing, preser
Control element responsive to a sensed operating condition
C422S051000, C435S004000, C435S287800, C435S288700, C436S530000, C436S528000, C436S535000, C436S169000, C436S170000, C436S901000, C436S805000
Reexamination Certificate
active
06224831
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a rapid, field-portable, modular, versatile and highly reliable assay device for substances, particularly drugs of abuse, and a method for making and using the device which provides a positive signal in the presence of a specific substance for which the device has been specifically adapted to test.
BACKGROUND OF THE INVENTION
U.S. Pat. Nos. 5,369,007, (hereinafter the '007 patent) and 5,200,321 (hereinafter the '321 patent), disclose a microassay on a card. In addition, a review of other devices and methods of microassay was provided in the '007 and '321 patents. The disclosure of those patents and the art cited therein is hereby incorporated by reference.
The '007 patent discloses a microassay card for detecting the presence of particular test substance in a liquid sample. The microassay card disclosed in the '007 patent consists of at least the following four functional layers of materials:
A. A paper label which can be eliminated if layer B has a printable or writable surface;
B. A well contained within a hydrophobic layer for receipt of a liquid test sample;
C. A supporting layer which is a substrate for a reagent that comprises either an anti-substance-enzyme conjugate bound to a substance which is immobilized on said layer or a substance-enzyme conjugate bound to an anti-substance which is immobilized on said layer;
D. A semi-permeable layer which controls the rate at which the test solution is able to leave the upper layers and enter the bottom layer;
E. A super-absorbent layer, which draws sample liquid down through the various layers of the device, containing a chromogenic substrate which changes color upon contact with either enzyme-conjugated antibody or enzyme-conjugated test substance released from the upper layers, depending on the nature of the moiety immobilized in layer C.
The instant disclosure provides a device and method similar in some respects to the device and method disclosed and claimed in the '007 patent. However, several novel features and improvements are provided herein such that the device of the instant invention is modular, in the sense that unitary portions of the device are separately manufactured and can be pre-assembled by the manufacturer for analysis of a particular analyte, or may be assembled in the field by the user, and thereby adapted for analysis of a wide range of analytes. In addition, because of novel features in the manufacture of the device of this invention, the reliability of the instant device is enhanced.
The '007 patent contains little disclosure about how the card can be manufactured and assembled. The disclosure concentrates on what is contained within each of the several layers. There is no teaching or suggestion of ways in which a particular device, once manufactured, could be modified to test for different substances based on the needs of the user. There is also no teaching or suggestion of a modular device which can be either pre-assembled or assembled in the field using highly reliable upper and lower card assemblies. Accordingly, from the disclosure of the '007 patent, one of ordinary skill in the art would understand that a different card would need to be specifically manufactured or purchased for each substance to be tested or each set of substances to be tested, or the card as purchased would need to have several wells, each pre-prepared for analysis of a particular test substance.
BRIEF SUMMARY OF THE INVENTION
The present invention concerns a modular microassay device comprising an upper card assembly and a lower card assembly which can be combined to form a microassay card. In one embodiment, the upper card assembly, which can be used for any microassay card so long as instructions imprinted thereon are modified or are modifiable, includes several layers with concentric holes in each layer such that a test sample can be placed in the wells formed by the alignment of the concentric holes in the several layers of the upper card assembly. In a preferred embodiment of the upper card assembly, these layers include:
Layer
1
: An imprintable label; this layer may be absent if layer
2
is printable; only the printing needs to be changed for the upper card assembly to be used in the production of a microassay card having any desired specificity, as defined by layer
4
(see below).
Layer
2
: A plastic sheet.
Layer
3
: A high tack, pressure-sensitive adhesive layer having a removable covering.
In one embodiment, the lower card assembly, which can be used for assembly of any microassay card, consists of several layers with concentric holes that can be aligned with those holes in the upper card assembly. In a preferred embodiment of the lower card assembly, these layers include:
Layer
5
: A plastic sheet.
Layer
6
: A semi-permeable membrane.
Layer
7
: A super-absorbent layer preferably containing a chromogenic enzyme substrate.
Layer
8
: A plastic sheet.
Prior to final assembly of the upper and lower card assemblies to form a complete microassay card, the user or manufacturer selects a layer of test substance-specific material, for interposition between the upper card and lower card assemblies. This interposed layer, referred to herein as Layer
4
, is preferably a cellulose-based material onto which is immobilized a reagent, such as an antibody which has bound to it its corresponding enzyme conjugated test substance, or a test substance which has bound to it its corresponding enzyme conjugated antibody. It is this feature which provides the user the option of adapting the card to test any substance for which a test substance-specific layer is available.
The subject invention also provides a method of mass producing the card components and mass assembly of cards adapted to different biochemical analyses, by using the same upper and lower card assemblies and changing only layer
4
for detection of a specific test substance.
Accordingly, it is an object of the invention to provide a rapid, field-portable, modular, versatile and highly reliable assay device adapted to test for specific substances, such as drugs of abuse and chemicals. In use, the subject device provides a positive signal in the presence of a specific substance. It is understood that the subject device, by selecting the appropriate antibody or antigen, can be utilized for other analysis tests, such as, for example, for the detection of water impurities, agricultural related tests for bacteria, traces of medication, pregnancy test, and tests used in pathology and medical fields.
Another object of the invention is to provide a method for making a rapid, field-portable, modular, versatile and highly reliable assay device for detecting substances, such as drugs and chemicals, wherein the device provides a positive signal in the presence of a specific substance for which the device has been specifically adapted to test.
Another object of the invention is to provide a method for using a rapid, field-portable, modular, versatile and highly reliable assay device to test for specific substances, such as drugs and chemicals, wherein the method provides a positive signal in the presence of a specific substance for which the device has been specifically adapted to test.
REFERENCES:
patent: 4459358 (1984-07-01), Berke
patent: 5196302 (1993-03-01), Kidwell
patent: 5200321 (1993-04-01), Kidwell
patent: 5369007 (1994-11-01), Kidwell
patent: 5686315 (1997-11-01), Pronovost et al.
patent: 5772961 (1998-06-01), Mico
patent: 0066648 (1982-12-01), None
patent: 0279097 (1988-08-01), None
patent: 0283613 (1988-09-01), None
patent: 0605828 (1994-07-01), None
Smith H. Kevin
Stafford Alan P.
Yarnes David
John Co., Inc.
Jones Deborah
McNeil Jennifer
Saliwanchik Lloyd & Saliwanchik
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