Limited dilution of S2 - Cloning S2 (Oct/01/2009 )

I have a stable cell line that produces a low yield of my protein so I'm trying to clone the cells by limited dilution. I have the cells in 15% heat inactivated FBS 100%conditioned media with hygro but my cells aren't dividing and it's been a week. Any suggestions?

Did you titrate a kill curve for the hygromycin before you used it?

Are the cells senescent?

My hygro is very low50yg/ml. at the low end of a kill curve I made a year ago one another clone. Many cells are dying but many more just seem stopped. I did this exact procedure 2y/o and it worked perfectly.