Chemistry: analytical and immunological testing – Involving an insoluble carrier for immobilizing immunochemicals – Carrier is organic
Reexamination Certificate
1997-01-27
2002-03-05
Chin, Christopher L. (Department: 1641)
Chemistry: analytical and immunological testing
Involving an insoluble carrier for immobilizing immunochemicals
Carrier is organic
C422S051000, C422S051000, C422S067000, C435S013000, C435S007920, C435S970000, C435S975000, C436S518000, C436S169000, C436S525000, C436S530000, C436S531000, C436S536000, C436S538000, C436S541000, C436S808000, C436S810000, C436S815000, C436S816000, C436S901000
Reexamination Certificate
active
06352863
ABSTRACT:
TECHNICAL FIELD OF THE INVENTION
The invention is in the field of ligand-receptor assays, including immunoassays, used for determining the presence or absence of an analyte in a biological fluid. More particularly, the apparatuses and methods of the invention relate to establishing the identity of a test subject and determining the presence or absence of at least one analyte in a biological fluid taken from the test subject using a single test device.
BACKGROUND OF INVENTION
For many years, those skilled in the art of ligand-receptor assays have sought an effective, inexpensive, and reliable device and method for detecting the presence and/or absence of antigens, antibodies, and the like. The art is replete with such devices.
For many years, those skilled in the art have also sought devices and methods for assuring that the sample being tested actually came from a certain individual. Many schemes, some elaborate, some simple, have been established to verify that the test sample was in fact produced by a particular individual. Similarly, many schemes exist to thwart matching a particular test result with a particular person.
For example, drug testing is now a routine procedure in athletics, prison, and the work place. The protocols involve testing individual fluid samples such as urine or blood to determine the presence of certain antibodies in the fluid sample; a positive result may be an indication of drug use.
Previously such testing has been accomplished by a series of tests which may involve shifting of the fluid being tested to different containers and removal of the fluid from the person being tested to a distant place. Oftentimes, fluid misplacement and/or substitution opened questions as to the chain of custody of the tested fluid. Thus, a problem which has occurred during such testing is that test fluids may be obtained from persons other than the person to be tested or that test fluids become mixed, lost, or cannot be specifically identified with that person after the test is returned from the laboratory. Also, these assays typically take too long to obtain timely results.
Other shortcomings are associated with many of the devices and methods currently used for the determination of analytes in biological fluids. Frequently, a certain level of skill is required to use or handle such devices to obtain satisfactory results. In addition, most of these devices require one or more additional reagents, and frequently a wash solution, to apply to the device during the course of the test. In many of these devices, due at least in part to the limited sensitivity of the devices, relatively large amounts of oftentimes expensive reagents or of test sample are required to give accurate results.
As noted above, the principles which form the basis for this type of detection is a person's immune system, i.e., the inherent capability of a mammal to respond to a foreign molecule, typically a macromolecule. Hereinafter, any molecule which is capable of eliciting such a response will be referred to as an antigen, i.e., an antibody generator. The proteins and protein fragments which are produced in response to the antigen will be referred to as antibodies or immunoglobulins.
SUMMARY OF THE INVENTION
The present invention overcomes problems inherent in known assay devices and systems through the use of a specifically designed assay device, preferably an immunoassay device which allows the determination of the presence or absence of an analyte in a sample, and preferably specifically identifies the person providing the sample.
The present invention is directed to a testing method and device and more specifically to a method and device for detecting the presence of an analyte, most preferably specific antigens or specific antibodies in a biological fluid. The present invention preferably also provides for positively identifying the individual tested.
The present invention provides an easily handled, disposable testing pad and a disposable test device suitable for detecting the presence or absence of an analyte and preferably for identifying the test subject. For example, a finger of the test subject may be coated with a labelled ligand and the finger may be pressed on a membrane substrate having a specific immobilized ligand bed to capture an analyte from a biological fluid while simultaneously providing an inkless (specific binding) visible fingerprint of the test subject so that positive identification of the fluid donor is irrefutably obtained. The fingerprint of the fluid donor obtained on the membrane may also include information about analytes, such as drugs, present in his body fluids at the time of performing the test. This information can be recorded or stored for positive identification when needed.
It is an object of the invention to assay a test sample for the presence or absence of an analyte while also identifying the subject being tested. Thus, problems of misidentification, chain of title, and delays may be eliminated.
It is an object of the present invention to provide a device for rapidly determining the presence or absence of an analyte taken from a test subject. It is also an object of the present invention to provide a device for rapidly determining the quantitative amount of an analyte in a sample taken from a test subject. Yet other objects of the present invention are to provide a device and a method of determining the presence or absence of a drug or drug metabolite in a test sample taken from a test subject and to provide a device and method determining whether a test subject is an acute or chronic drug abuser.
Another embodiment of the present invention, where identifying the test subject by a fingerprint is not critical, involves applying the sample of body fluid or a labelled ligand to the membrane with the pressure of a transfer means or applicator that is part of the test device. In contrast to similar known devices which apply liquid test samples and/or reagents dropwise to the surface of a reaction medium, the present invention, in which liquid test samples and/or reagents are applied and maintained under pressure on the surface of the reaction medium for a short duration, requires smaller amounts of test sample and reagents and demonstrates higher sensitivities than known devices.
A device according to the present invention which uses this principle is an enclosed assay test device. A preferred embodiment is one in which the assay test device includes a housing, a reaction medium having at least one reaction zone located in the housing, a medium containing a signal-producing or analyte-indicating agent located in the housing, and a medium for containing a test sample located in the housing. Both the medium containing a signal-producing agent and the medium for containing a test sample located in the housing are movable independently between a first position in spaced relationship to the reaction medium and a second position in substance-transferrable contact with the reaction medium. Preferably this is a self-contained test device.
A particular embodiment of this invention includes an assay test device employing a two-part housing. In one embodiment of the device, a reaction medium having at least one reaction zone is mounted in a first part of the housing. In the second part of the two-part housing is located a medium for containing a portion of a test sample. The medium for containing a portion of a test sample and the reaction medium are so arranged in the two parts of the housing that when the housing parts are brought together in a closed relationship, there is substance transferrable contact between the medium for containing a portion of a test sample and the reaction medium. In addition to at least one reaction zone, the reaction medium preferably has a control zone which is provided to identify the test subject by a fingerprint or like means if desired. Such a device may be designed as a self-contained assay device. As used herein, the term “self-contained” means that the device may be used without the addition of additional reagents or solutio
Chin Christopher L.
La Mina, Inc.
Rothwell Figg Ernst & Manbeck
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