293T cells - (Aug/03/2007 )

anyone has any ideas of how long the T antigen can stay within 293T cells? I am using these cells for protein expression and I am worried that the T antigen is lost and hence this results in no expression. My cells are now in passage 27. Are these desireable for protein expression?

Thank you.

well 293T cells are selected stable cell lines which express the large T anigen from SV40 virus. I think it's neo as genehunter-1 raised. So if you suspect a low level, select with neo should recover cells that express the antigen.

Unsually not. You can select again with neo if you suspect your cells have changed over time.

we add genticin every 3rd passage of the293Ts to keep them selected.