Question

what is the percent viability of cells if 5 cells are clear and 15 cells are blue?

Answer 1

In cell viability assays, the viable cells retain a clear cytoplasm because of the cell membrane which is intact. Whereas, the damaged or non-viable cell cytoplasm becomes blue in colour as the dye penetrates the cytoplasm because in dead cells the cytoplasm becomes porous.

If we want to calculate the viability%, we have to use the following formula-

Total viable cells/total number of cells( viable+non viable) ×100

Here, the viable cells are 5 in number and the number of total cells is 15+5= 20

Hence, the viability %= 5/20×100 = 25%