reasons for apoptosis in primary cell culture? - (Mar/15/2006 )

I was wondering if it is normal in primary confluent cultures to have a basal rate of apoptosis...
anyone knows possible reasons for this?

thanks!!

well, sure

you only get a limited number of passages with primary cells, right? some of the cells will become senescent, hang on for awhile, and then become apoptotic; this will increase as the number of passages increases

I don't think the numbers are supposed to be very high, you might contact your vendor or check the literature for your cell type if they seem abnormal

Thank you for your answer.
I do primary cell culture of rat spinal astrocytes. I pass them once, use them and then I throw them away, two weeks old.
I'm measuring the proliferation of this astrocytes, and found that despite being a confluent monolayer, they keep dividing. About 5% of the astrocytes are proliferating in this conditions, so I wondered if maybe a basal rate of apoptosis could account for this.
What do you think?