Lyophilized standards for the calibration of real time PCR assay for hepatitis C virus RNA

Background Since October 1997, an international standard for hepatitis C virus (HCV) nucleic acid amplification technology assay, 96/790, has been available. We compared a series of lyophilized standards with known HCV RNA concentrations against the international standard in fluorescence quantitative PCR detection. Methods A series of lyophilized sera were calibrated by ROCHE COBAS AMPLICOR HCV Monitor test against the international standard and sent to various manufacturers to analyse the samples using their own kits. Then calibration curves from the series were compared with that obtained from the external standard calibration curve with the manufacture’s series. Results The standard calibration curve with the series of lyophilized serum showed an excellent correlation (R2>0.98), slope and intercept that were similar to those from the manufacture’s series. When the standard calibration curve from the series of lyophilized standards were used to define the values of the given sample, lower coefficients of variation between kits from different manufactures were obtained. Conclusion The results showed that the lyophilized standards could be used to setup the standard calibration curve for clinical HCV RNA quantitative PCR detection.