Genotyping of hepatitis C virus by melting curve analysis with SYBR Green I

Background: Recent studies have focused on whether different hepatitis C virus (HCV) genotypes are associated with different profiles of pathogenicity, infectivity, and response to antiviral therapy. We needed to develop a convenient screening test for HCV genotypes 1 and 2. Method: We tested 55 patients with known chronic HCV infection. Viral RNA was extracted from serum samples using an automatic viral RNA purification system, and HCV genotypes were determined by reverse transcriptase-polymerase chain reaction using LightCycler melting curve analysis with SYBR Green I. Results: HCV RNA was detected in all samples and each genotype was determined. The mean (standard deviation) melting temperatures for subtypes lb (n = 32), 2a (n = 15) and 2b (n = 8) were 93.14°C (0.51°C), 91.08°C (0.49°C) and 91.77°C (0.27°C), respectively. Genotypes 1 and 2 were differentiated within 3 h by this method. Conclusions: Our melting curve analysis is a rapid and convenient screening test for differential identification of HCV genotypes 1 and 2.