Cell viability test with trypan blue

Trypan blue staining assay is a commonly used method to determine cell viability. The assay is based on the principle that trypan blue is excluded from viable cells but penetrates and stains dead cells. In this assay, cells are treated with trypan blue solution, which gives the dead cells a blue color, while viable cells remain unstained. Cells are mixed in a 1:1 ration with 0.4% trypan blue solution. The number of alive and dead cells is then counted under a microscope using a hemocytometer. The percentage of alive cells is calculated by dividing the number of alive cells by the total number of cells.