US 6,306,616 B1Granted

Adsorption type confirmatory assays

AssigneeMicrogenics Corporation

InventorJeffrey E. Shindelman

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Abstract

The invention relates to an assay system for the improved detection of analytes, and the ability to distinguish them from cross-reacting substances. Samples giving a positive reaction in a direct assay test are treated with a neutralizing antibody that inhibits reactivity of the true analyte, but not the interfering substance. In adsorption type confirmatory assays, the neutralizing antibody is provided in an amount sufficient to adsorb the analyte but not all of the interfering substance. When retested in an immunoassay, the neutralized sample gives a negative result if it originally contained the true analyte. Samples giving a positive reaction in both the direct and confirmatory tests are marked as containing an interfering substance. The confirmatory assay easily distinguishes the true analyte and reduces the rate of false positives, even when the interfering substance is unknown and present at high concentration.

Claims26

Dependent claims

An assay method for distinguishing between a small molecule analyte selected from the group consisting of LSD, LSD metabolites, and combinations thereof and an interfering substance in a sample comprising the steps of:

a) preparing a reaction mixture comprising the sample, a hapten derivative that provides a signal and a detecting antibody that binds with the hapten derivative to yield a detectable signal in the assay, wherein the detecting antibody binds the hapten derivative in a manner that is specifically inhibitable by the analyte;
b) measuring the amount of the detecting antibody bound to the hapten derivative in step a);
c) treating the same sample or duplicate thereof with a neutralizing antibody in an amount sufficient to prevent the analyte but not all the interfering substance in the sample from binding the detecting antibody;
d) preparing a reaction mixture comprising the treated sample or duplicate, a hapten derivative that provides a signal, and a detecting antibody that binds with the hapten derivative to yield a detectable signal in the assay, wherein the detecting antibody binds the hapten derivative in a manner that is specifically inhibitable by the analyte;
e) measuring the amount of the detecting antibody bound to the hapten derivative in step d);
f) determining the difference in signal measured in step e) from step b);
and
g) comparing the difference in signals in steps b) and e) to determine (i) the presence of analyte in the sample if the amount measured in step b) is significantly different from the amount measured in step e);
or (ii) the presence of interfering substance in the sample if the amount measured in step b) is not significantly different from the amount measured in step e).

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/049,464Filed 27 Mar 1998
Granted: 23 Oct 2001
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

G01N 33/94
Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing:…
Y10S 436/815
Chemistry: analytical and immunological testing: test for named compound or class of compounds
G01N
Investigating or analysing materials by determining their chemical or physical properties
Y10S
Technical subjects covered by former uspc cross-reference art collections [xracs] and digests