C-terminal of PB2  deep sequencing during H9N2
H9N2 virus packaged with either avANP32A or huANP32A were blind passaged six times in MDCK cells. Each passage has four independent populations for each type of virus. Viral RNAs were extracted and the C-terminal of PB2 was amplified and deep sequenced to monitor the residue phenotype of PB2 627 and 701 positions during passages in MDCK cells