Hello friends,

I want to use my stable transfected cells for soft agar colony formation assays. I wonder whether the selection antibiotics such as G418 should still be used in the medium used to prepare the top agar. No protocol mentions that. If G418 is withdrawed, I fear that the cells may behave differently, am right?

thanks for your thoughts.

Has anyone noticed that transformed cells may lose their ability to form colonies if they switch from medium with selection antibiotics to without it?

As far as i know, the agar should not contain g418. however, i don't know why, so if someone could shed some light on that, i'd be grateful.

as for the transformed cells switching with antibiotics... never really noticed. though i did notice that some cells induced to stop proliferating and enter differentiation, revert back to proliferating when fresh media is added. but that's not my experiment, so i won't say more.

V