Cell Counter

Cell counters are used to count live and/or dead cells in a cell culture. Automated cell counters operate either via electrical impedence (“Electrical Sensing Zone” method), direct imaging (either on a disposable slide or in a flow chamber), or flow cytometry. The most important variable to consider in selecting a cell counting solution is the ability to assess cell viability. Electrical impedence (the Coulter Counting approach) generally cannot distinguish live from dead cells (except by size); but imaging-based approaches can, by using trypan blue to stain dead cells, just as in classic hemacytometry. The evaluation of cell population density (i.e. the total number of living cells in the culture) and cell viability (i.e. the percentage of living cells in the sample) is fundamental during biology studies. The majority of laboratories engaged in cell biology routinely perform cell viability and counting analysis for different purposes, ranging from ecosystem investigation to proliferation studies, in both 2D (two-dimensional) and 3D (three-dimensional) cell cultures. Manual cell counting is generally accomplished using a hemacytometer, a glass slide etched with a counting grid.