So the way I've been doing it is I suspend the cells in 5mL DPBS, take a small sample and count it, then centrifuge, aspirate off supernatant, and resuspend pellet in 1:1 cell PBS and 10% formaldehyde. I worry that by counting them at this stage, I am not accounting for cells that may be lost in the next steps. Is it possible to take my finished product, the fixed cells, and combine them with trypan blue at a 1:1 ratio and then get an accurate count with the Countess II? Or will fixation affect the way trypan blue stains cells?
Thanks!