Homogeneous quantitative assay of hepatitis C virus RNA by polymerase chain reaction in the presence of a fluorescent intercalater.

We have developed a homogeneous quantitative assay of DNA/RNA by performing PCR in the presence of an oxazole yellow derivative, a fluorescent DNA intercalative dye, and monitoring the fluorescence intensity of the PCR reaction mixture during PCR cycles. We have demonstrated the applicability of this assay by use it to quantify hepatitis C virus (HCV) RNA of serum samples from patients with chronic hepatitis C. This assay gave efficient and reproducible results in a clinically useful dynamic range below 10(-6) copies of HCV RNA for interferon therapy.