2.2 Viruses and cells.
The EA H1N1 SIVs, A/swine/Guangxi/18/2011 (GX/18) and
A/swine/Guangdong/104/2013 (GD/104), were isolated in slaughterhouse
during routine surveillance from 2010 to 2013. HEK293T and Sp2/0 cells
were maintained in Dulbecco’s modified Eagle’s medium and RPMI 1640
medium with 10% fetal calf serum at 37°C in 5% CO2,
respectively.