The present invention relates to the detection of the presence of reverse transcriptase enzymatic activity in eukaryotic cell lines. Specifically, the present invention comprises a method for discriminating between endogenous reverse transcriptase activity in a substrate cell line (e.g., avian) used as substrates for the manufacture of biological products (including viral vaccines) from exogenous infectious retrovirus by using a combination of transmissibility assay (viral replication) and PBRT assay (RT-PCR). Appropriate levels of viral amplification and number of PCR cycles are determined and employed that permit detection of exogenous infectious RT activity but not endogenous RT activity.

A method is provided for the determination of the presence of a reverse transcriptase in a sample liquid. In an aqueous medium, at least an adenine ribopolynucleotide RNA template (poly A), an immobilized oligodeoxythyminenucleotide and a biotinylated deoxyuridine triphosphate are reacted in the presence of the sample liquid. After separation of the reacted and the unreacted biotinylated deoxyuridine triphosphate from each other, the reacted or the unreacted biotinylated deoxyuridine triphosphate is detected. Also provided is a method for the determination of infection of a patient to a retrovirus. The reaction is conducted in the presence of a sample body fluid and the reverse transcriptase. After the detection of the reacted or the unreacted biotinylated deoxyuridine triphosphate, the reverse-transcriptase-neutralizing and/or inhibiting antibody titer in the sample body fluid is determined.

Method and compositions for infectious disease diagnosis and epidemiology involving labeled nucleotide probes complementary to nucleic acid coding for a characteristic pathogen product. Clinical isolates are cultivated, expanding the number of microorganisms, the resulting colonies lysed, the genome normally denatured and then fixed. Alternatively, clinical samples (stool, sputum, pus, etc.) are spotted onto an inert support. The sample is treated in such a way that the DNA is liberated from microbes present in the sample and complexed onto the support. The DNA is normally denatured and fixed in this process. Subsequently, a labelled polynucleotide probe specific for a DNA sequence characteristic of a pathogenic product suspected of being present in the clinical sample is contacted with the fixed genomic single stranded nucleic acid under hybridizing conditions. Hybridization of probes to the single stranded nucleic acid is diagnostic of the presence of the pathogen.

The effects of a substance on the replication process in vitro of ADN separated from sound tissues (check tissue) on the one hand and of DNA separated from cancerous tissue (cancerous DNA) on the other hand, are being compared. Cancerigenic substances are identified since they stimulate the replication of cancerous DNA more strongly than the replication of check tissue; specifically anticancerous substances since they inhibit the replication of cancerous DNA but not the replication of check tissue, toxic substances since they inhibit the replication of cancerous DNA as well as that of check tissue; and neutral substances since they do not have any effect either on the replication of cancerous DNA or on that of check tissue.

The sequence of the protein coding regions of the bcl-2 gene are provided as well as bacterial clones which produce the proteins. Assays are provided for detecting a class of B-cell neoplasms associated with a chromosome translocation between chromosomes 14 and 18. This translocation is involved in the majority of cases of human follicular lymphomas. One assay employs an antibody which is immunoreactive with a human protein which is over-expressed due to the chromosome translocation. Another assay involves measurement of the amount of mRNA which hybridizes to the gene proximal to the translocation break-point.