A hemocytometer is a specialized microscope slide used for counting and analyzing cells in a liquid sample. It consists of a thick glass slide with a grid pattern etched into its surface, allowing for precise measurement of cell concentration. Researchers often use it in laboratories to assess blood cells, bacteria, or other microorganisms. To use a hemocytometer, a small volume of the sample is placed in the chamber, and the cells are counted under a microscope. This method provides valuable information about cell viability, concentration, and morphology, making it essential in fields like hematology and cell biology.