I believe that the reason why you want to rinse the cells prior to the addition of the
trypsin is due to the inhibition of trypsin by serum (Ca++, other stuff?). If your cells
are kept with media and serum then you should wash them. If in serum free than it is
OK to trypsinize without washing. Even if you had the cells with serum if you are
adding an excess of trypsin you may be able to digest enough to separate the cells.
In our lab we use a Puck's-EDTA solution to rinse just to be sure and then we
If anyone has other opinions or comments please let me know, thanks.