This video is about hemocytometer calculation, for RBC count, WBC count etc The hemocytometer (or haemocytometer) is a counting-chamber device originally designed and usually used for counting blood cells. The hemocytometer was invented by Louis-Charles Malassez. Cell counting proceture using hemocytometer, consists of a thick glass microscope slide with a rectangular indentation that creates a chamber. This chamber is engraved with a laser-etched grid of perpendicular lines. The device is carefully crafted so that the area bounded by the lines is known, and the depth of the chamber is also known. By observing a defined area of the grid, it is therefore possible to count the number of cells or particles in a specific volume of fluid, and thereby calculate the concentration of cells in the fluid overall.