Abstract: The PDL1 monoclonal antibody was transiently expressed by using HEK293 6E cells. We cultivated HEK293 6E cells in serumfree suspension and selected the optimum growth medium, investigated the transfection conditions of HEK293 6E cells, including culture medium varieties, the mass ratio of DNA and PEI, and cell density while transfecting, then identified the harvested antibodies by SDSPAGE and ELISA. The results show that the best transfection conditions were as follows: A style, a serumfree culture medium, a cell density of 2×106 cells/mL and m(DNA)∶m(PEI)=1. The highest yield of antibody was 170.9 μg/mL at the fourth day after transfection, the molecular weight of the heavy chain of the harvested PDL1 antibody was about 50 000 and that of the light chain was about 25 000.

Key words: anti-human PD-L1, transfection, transient expression, antibody