To understand the epidemics and antigenic drift of influenza viruses in China from 2000 to 2001.
The viruses were grown in embryonated hen eggs with 9 - 10 days old. The egg allantoic fluids with influenza viruses were used. Virion RNA was transcribed into cDNA by reverse transcriptase while cDNA amplified by PCR. Products of PCR were… (More)