Abstract: An ultrasensitive procedure for the detection of reverse transcriptase (RT) is proposed, which is divided into three steps:In the first step the sample is processed by placing a template-primer combination in a reaction mixture and using the RT activity present in the pretreated sample to provide a nucleic acid to be amplified in a given nucleic acid amplification procedure so as to ensure that this is only provided if there is RT activity in the sample.In the second step the nucleic acid to be amplified is amplified, the result being an amplification product.In the third step the amplification product is analyzed and identified.Compared to conventional RT assays a several million fold increase of sensitivity is achieved, thus the ultrasensitive detection of RT activity is made possible, that is the detection of all retroviruses as well as other retroelements containing or expressing active RT.

Abstract: The invention is a simple and rapid method for immune complex dissociation and destruction of rheumatoid factors. It permits the quantitative measurement of the total, i.e., free and immune complex-bound, antigen contained in a test sample. The method involves heating the test sample to a point sufficiently above 65.degree. C. at which the antigen-binding function of antibodies is destroyed. As a consequence, interference by rheumatoid factors is eliminated and the antigen is released from immune complexes, after which it can be measured in an antigen assay that recognizes the heat-denatured antigen.