Problem with HEK stable cell line - (Nov/21/2011 )

Hi everybody,
I am a new user on this wonderful forum.
I just had a problem with a stable HEK line this week end.
I previously have had good transfection efficiency. I selected using 0.5 mg/ml G418 (established last year with a kill curve)
On Friday, after 10 days of selection, all the cells on my non-transfected dish were dead.
I was up to trypsinise my cells, but my chief told me to wait over the w/e.
yesterday, almost all my cells were detached, and attached in blocks...
I know that HEK are notorious for poor attachment to the surface...

I am starting a new selection. What can I change in my protocol?
Many thanks and sorry for this long message

It sounds like you just let them get over-confluent, try trypsinising them, they should be OK.