To optimize the conditions for transient transfection in HEK293F cells and improve the production of PDGFR-β

DNA（pXLG-PDGFR-β）and PEI were separately diluted in ultra-pure water

mixed together

and incubated at room temperature. The PEIDNA complex was then added to the cells

and the culture was incubated at 37 ℃with 6% CO

2

with agitation at 180 r/min

then incubated for 7 days. The PDGFR-β/Fc concentration in the culture medium was determined by sandwich ELISA.The conditions including cell density

DNA concentration and ratio of DNA to PEI

as well as other effectors such as adding of VPA and peptone were optimized. The results showed that transient gene expression yields of PDGFR-β/Fc can be maximized under following conditions:4×10

6

cells/mL

2.0 μg/10

6

cells DNA

1∶2 ratio of DNA and PEI and polymerize 5 minutes. The productivity can be further increased with adding of 3 mmol/L VPA

glucose and 1 g/L TN1. The experiment showed that when the conditions for transient transfection of HEK293F cells were optimized

the PDGFR-β/Fc yields up to 55 mg/L were achieved at the conditions

which laid a foundation of PDGFR-β/Fc expression for larger scales transfection in HEK293F cells.