prepare cell suspension at a high concentration (ca 106 cells/ml)
take a clean hemocytometer slide and fix the coverslip in place
mix one drop of cell suspension with one drop of trypan blue (0.8mM in PBS)
take 10 ul into the tip of a pipet
transfer immediately to the counting chamber
wait 2 min (no more then 2 min)
count the cells lying within the counting area.
count the number of stained cells and the total number of cells
* Viable cells exclude trypan blue, while dead cells stain blue due to trypan blue uptake.
Test for cell viability