Multicyclic reverse transcription-polymerase chain reaction assay system for quantitation of GB virus-C/hepatitis G virus RNA in serum

Abstract

A new quantitative reverse transcription-polymerase chain reaction (RT-PCR) method is described for analyzing the amount of GB virus-C (GBV-C)/hepatitis G virus (HGV) RNA in serum. This multicyclic RT-PCR (MRT-PCR) method used oligonucleotide primers deduced from the 3′ noncoding region (3′NCR) that is highly conserved among GBV-C/HGV isolates. Quantitation of GBV-C/HGV RNA using MRT-PCR ranged between 10 2 and 10 10 copies/ml when PCR cycle number was regulated at exponential amplification of the products. Competitive RT-PCR (CRT-PCR) was carried out with mutant RNA and sample that had been measured by MRT-PCR. Quantitation of GBV-C/HGV RNA using both methods agreed. MRT-PCR detected viral RNA in a single step PCR, and demonstrated a high degree of sensitivity that was equal to that of the RT-PCR procedure, which used nested primers deduced from the non-structural (NS) 3 region. The MRT-PCR method for quantitation of GBV-C/HGV RNA in serum may prove useful for diagnosis.