Geneticin Resistant Cell Lines and Stable Transfection - (Apr/15/2013 )

I am attempting to make a stably transfected cell line for the purpose of propagating a virus. The ideal cells for propagating this virus appears to be resistant to even 2500 ug/mL of geneticin. The geneticin does not expire for another year. I began the selection two days ago and do not visualize any appreciable cell death in either of the two cell lines. Does anyone have any experience with producing stable cell lines in cells which are resistant to geneticin?

Two days is a bit short for geneticin, wait at least a week.