What are the differences in HEK293 vs 293T cell lines for packaging?
HEK293 cells are the parental line for 293T. The ""T"" means that it expresses the Large T antigen which is important for replicating plasmids containing an SV40 origin of replication to high copy number in the transfected cell. The SV40 origin of replication is present on our lentiviral packaging and vector constructs and therefore should be transfected into 293T cells for virus production. Parental 293 cells do not contain the T antigen and would not produce sufficient titers.