counting cells - (Aug/04/2010 )

Hi all,
I count cells without centrifuging and resuspending them but my supervisor insists on centrifuging and resuspending cells before counting them.
i dont understand does it make any difference because we are counting only the live cells and not the dead cells and debri..??
I have tried doing bothways at the same time there was a neglible difference. does any body else think my supervisor is right..?? if so is there a scientific reason behind this or is it just one of those "it's in the protocol" thing.


thanks in advance
kartheek

The reason to resuspend the cells to know exactly the final volume of cells in the exact volume added after centrifugation. I dont think there is any other scientific reason for that

I think it depends on the purpose of the count. For example, if you are determining cell density before passing your cells, then it would be worthwhile to count following the centrifugation as you are most interested in the live cells anyway.Although, for record keeping of how your cells are growing normally, you should count your cells before centrifuging them. Moreover, if you are counting cells to check viability because of an experiment or some other alteration, then the cells should not be spun down before counting.

Those are just my thoughts...

Can you tell me the detailed process and requirements for the U937 cell culture?
Plzzzzzz reply soon