# Cell viability calculation

To calculate cell viability of the cell culture, Trypan blue is normally used. This is a vital stain that is permeable to cells depending on their membrane integrity. Therefore, cells visualized in blue under the microscope will be assumed as dead while the rest would be living cells. To use Trypan blue you just need to add it to the cell solution (commonly using 1:2 ratio), count the total number of living cells as well as the total number of dead cells, and calculate the percentage.

Example:

Live cell count = ^{6} cells/mL

Dead cell count = ^{5} cells/mL

Total number of cells = ^{6} cells/mL

^{6} / 2.994 x 10^{6}) x 100 = 95.5%