How to Count Cells with a Hemocytometer

Cell counting is an integral part of determining cell concentrations for plating in culture, determining cell viability, and assessing the results of cell isolation procedures. It is recommended to perform an initial cell count prior to cell isolation; this number can then be compared to the cell count after cell isolation to calculate cell recovery. Additionally, viable cell counts should be performed when a decrease in cell viability may be expected, for example, when working with cryopreserved cells or cells manipulated ex vivo.