[Quantitative PCR system].

We evaluated a real time quantitative PCR assay using dual-labeled fluorogenic probes for clinical application. Preliminary study using the house-keeping gene, beta-actin confirmed that this method was accurate and reproducible for the quantitative detection of the genes. The system also has merit with regard to the dynamic range of the starting target molecule determination. We then investigated DNA copies of cytomegalovirus (CMV) gene in vivo. The results demonstrated on association between the quantitation of CMV-DNA copies and clinical manifestation associated with CMV infection of immunodeficiency states or infantile hepatitis. It was also successful for quantitative estimation by RT-PCR. Namely, the assay made it possible to discriminate drug-sensitive leukemia cells from resistant cells based on the MDR1 gene and dCK gene. Real time quantitative PCR assay may be useful in a variety of clinical fields.