Beckman Instruments, Inc.

Relia Diagnostic Systems, LLC

Praxsys Biosystems, Inc.

Alan J Polito

Robert K Dinello

Richard M Thayer

George H Sierra

Stella Quan

Alan C Phillips

Stuart K Neubarth

William S Knight

Dennis Nixon

Henry J Wieck

Kurtis R Bray

Anthony K Cheng

Stuart Neubarth

An embodiment of the present invention provides a-method for performing a lateral flow assay. The method includes depositing a sample on a test strip at an application region, detecting a first detection signal arising from the test strip in the first detection zone, and generating a baseline for the first measurement zone by interpolating between values of the detection signal outside of the first measurement zone and inside of the first detection zone. The method may include locating a beginning boundary and an ending boundary for the first measurement zone on the test strip. Additional detection zones having measurement zones may also be incorporated with the embodiment.

Method and apparatus for performing a lateral flow assay

A test strip and method for detecting an analyte present in a sample. The test strip comprising: a buffer addition zone to which a buffer may be added; an absorbent zone proximal to the buffer addition zone; one or more test zones distal to the buffer addition zone, at least one of the test zones including a first analyte binding agent immobilized therein which is capable of binding to the analyte to be detected; a terminal buffer flow zone distal to the one or more test zones, the absorbent zone being positioned relative to the buffer addition zone and having an absorption capacity relative to the other zones of the test strip such that when a volume of buffer within a predetermined buffer volume range for the test strip is added to the buffer addition zone, a distal diffusion front of the buffer diffuses from the buffer addition zone to a distal diffusion point within the terminal buffer flow zone and then diffuses proximal relative to the one or more test zones; and a sample addition zone distal to the terminal buffer flow zone to which a sample may be added.

Prewetting lateral flow test strip

Prewetting stop flow test strip

An embodiment of the present invention provides a method for performing a lateral flow assay. The method includes depositing a sample on a test strip at an application region, detecting a first detection signal arising from the test strip in the first detection zone, and generating a baseline for the first measurement zone by interpolating between values of the detection signal outside of the first measurement zone and inside of the first detection zone. The method may include locating a beginning boundary and an ending boundary for the first measurement zone on the test strip. Additional detection zones having measurement zones may also be incorporated with the embodiment.

A test strip adapted to receive a sample and detect an analyte therein is provided. The test strip comprises a sample addition zone to which a sample may be added; an absorbent zone proximal to the sample addition zone; one or more test zones distal to the sample addition zone, at least one of the test zones including a first analyte binding agent immobilized therein which is capable of binding to the analyte to be detected; and a terminal sample flow zone distal to the one or more test zones, the absorbent zone being positioned relative to the sample addition zone and having an absorption capacity relative to the other zones of the test strip such that a distal diffusion front of a sample added to the sample addition zone diffuses from the sample addition zone to a distal diffusion point within the terminal sample flow zone and then reverses direction and diffuses proximal relative to the one or more test zones.

Bidirectional lateral flow test strip and method

A novel competitive assay for theophylline wherein caffeine-like (7-substituted) labeled conjugates are used to detect the presence and/or amount of theophylline present in a test sample. The use of such conjugates in a competitive assay for theophylline results in improved sensitivity of the assay method. Where the assay method is a nephelometric or turbidimetric inhibition immunoassay procedure, the assay was found to be less temperature dependent than prior art immunoassays.

Novel competitive assay for theophylline and reagent for use therein

A T.sub.3 uptake polarization fluoroimmunoassay where a sample is assayed by contacting a serum sample with T.sub.3 to form a solution, contacting the solution with a separating agent and incubating the same, separating T.sub.3 bound to the separating agent from the serum sample, contacting the T.sub.3 bound to the separating agent with an antibody against T.sub.3, incubating and separating the agent-anti-body combination, separating free anti-body and contacting the free antibody with fluorescent labeled T.sub.3 and fluorometrically measuring the fluorescence polarization.

T.sub.3 Uptake polarization fluoroimmunoassay

A polarization fluoroimmunoassay for T.sub.3 or T.sub.4 thyroid hormones where a serum sample is assayed by contacting the sample with a base to denature the thyroxine binding globulins and thereby form a solution, incubating the solution, contacting the solution with a separating agent and separating bound thyroid hormone from the serum, contacting the separating agent with bound thyroid hormone with an antibody against the thyroid hormone, incubating the separating agent-antibody combination, separating free antibody and thyroid hormone bound antibody from the separating agent, contacting the free antibody with fluorescent labelled thyroid hormone and measuring the fluorescence polarization as an indication of the thyroid hormone in the sample.

Thyroid polarization fluoroimmunoassay

An improved T.sub.3 uptake test procedure characterized in that the separating agent employed therein comprises bovine serum albumin covalently coupled to a derivatized polysaccharide matrix by a bifunctional coupling agent selected from a group consisting of ##STR1## WHEREIN N IS AN INTEGER FROM 1 TO 6 AND WHEREIN E IS AN INTEGER FROM 1 TO 2. A separating agent comprising bovine serum albumin covalently coupled to a derivatived polysaccharide matrix by a bifunctional coupling agent selected from a group consisting of ##STR2## WHEREIN N IS AN INTEGER FROM 1 TO 6 AND WHEREIN E IS AN INTEGER FROM 1 TO 2.

T.sub.3 uptake test employing covalently bound bovine serum albumin

A method of separating free from bound fractions in an immunoassay procedure of the type wherein a solution is contacted with a composite comprising a finely divided, activated, polysaccharide matrix covalently coupled to a primary antibody, wherein the improvements comprise:

Immunoassay procedure employing novel immunochemical composites

A method of separating free from bound fractions in an immunoassay procedure of the type wherein a solution is contacted with a composite comprising a derivatized polysaccharide matrix covalently coupled to an antibody by a bifunctional coupling agent, wherein the improvement comprises selecting said bifunctional coupling agent from a group comprising ##STR1## WHEREIN N IS AN INTEGER FROM 1 TO 6 AND WHEREIN E IS AN INTEGER FROM 1 TO 2.

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Danville, CA, United States of America

Alan J Polito