Keratinocytes don't flatten - (Oct/12/2011 )

how long does it usually take for primary human keratinocytes to flatten after subculturing?
My cels after 22h are attached to the flask bottom but still rounded. Does this mean they are in a poor condition and that they won't be suitable for performing experiments (transfection and protein extraction - they have to survive seeding and at least 48 hrs)

Will changing the medium help them in any way?

How many passages are they?

Changing the medium probably won't help - they secrete growth factors that help them survive.

They're on 4th passage. I know it's much for primary cells but I need them only to check the technique before starting a real experiment, so they don't have to be super-wee-good, and before the passage they were very viable.