Cell proliferation is the increase in cell number as a result of cell growth and division. The accurate assessment of cell number and cell proliferation is useful in many high content assays and is a key readout in cytotoxicity and apoptosis applications. Cell proliferation is also a very sensitive indicator of cell stress since it requires intact cell structures and function.

Cell culture at two different cell densities labeled by a non-specific fluorescent dye; individual cell borders are identified.