Patent ID: 6083689
Filing Date: 2000-07-04
Classification: C12Q,G01N,Y10S

Abstract:
An immunoassay method to detect or detect and quantitate an analyte in a test sample comprising:(a) contacting said test sample with a conjugate of an antibody coupled to variant DNA as a component of a signal amplification system, wherein said variant DNA is a substrate for an RNA-dependent RNA polymerase, and wherein said antibody is either specific to the analyte under assay or is specific to another antibody or to an immunocomplex that is specific to the analyte under assay;(b) incubating said conjugate with said test sample, or incubating said conjugate with said test sample and with said other antibody or immunocomplex that is specific to the analyte under assay for an appropriate amount of time;(c) separating any conjugate that is bound to analyte, either directly or through said other antibody or said immunocomplex, from conjugate that is not bound to an analyte;(d) transcribing said variant DNA of conjugate that is bound to the analyte, to RNA, and replicating the RNA transcripts, by contacting said variant DNA template and RNA transcripts with a sufficient amount of both an appropriate RNA-dependent RNA polymerase and ribonucleotides; and(e) determining whether any variant RNA is replicated in step (d) and correlating RNA replication products with analyte being present in said test sample; or detecting and quantitating variant RNA replicated in step (d), and correlating the quantity of said RNA replication products with that of analyte present in said test sample.