Culturing eukaryotic cells is to grow cells outside of their natural environment. Cells, such as mammalian cells thrive in a CO2 saturated environment. This can be accomplished using a CO2 incubator, with temperature, humidity, CO2 and O2 regulation. Quantifying the amount of cells in a cultured sample is indicative of the efficacy of the cell culturing process. Cells may be counted using a hemocytometer and a microscope. However, for efficient and accurate counting, a Revolutionary Science automated cell counter, the RevCount may be preferred.