[Development and verification of reference nucleic acid materials of H9N2 influenza viruses by real-time RT-PCR]

The HA gene of H9N2 influenza virus (A/chicken/Hunan/04.14 (H9N2)) was amplified and sequenced. The RNA was synthesized by in vitro transcription. The RNA transcription solutions were diluted to 10⁹ copies/μL using the RNA storage solution. The aliquoted RNA solutions were used to evaluate the homogeneity and stability. The results were determined by the average value obtained from four independent laboratories. Furthermore, the fluorescence quantitative RT-PCR method was also developed to verify the detection accuracy of clinical samples. The detection limit of this method is approximately 10 copies. Taken together, the RNA transcription solution established in our study can used as positive standard reference for rapid detection of H9N2 influenza virus.