Wiktionary
alt. (label en American spelling) A device used to count the number of blood cells in a volume of blood. n. (label en American spelling) A device used to count the number of blood cells in a volume of blood.
Wikipedia
The hemocytometer is a device used to count cells. It was originally designed for the counting of blood cells.
The hemocytometer was invented by Louis-Charles Malassez and 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. 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.
Usage examples of "hemocytometer".
And helping to record data of such exacting minuteness, Patrick felt, as he often felt in the midst of such experiments, which were essentially the counting of microbe cells with a high-tech hemocytometer, as if he were an intruder in a world that, if he descended into it for a split second, would devour him rapaciously, reducing him to mnere chemicals and a throbbing current called "life.