When performing a red cell count, what is the factor by which the counted cells are multiplied?

In the context of performing a red cell count, the correct factor by which the counted cells are multiplied is 10,000. This calculation is necessary because the red blood cells are often enumerated using a hemocytometer—an instrument that allows for counting cells in a defined volume of fluid. The volume of the chamber in which the cells are counted is very small, and in order to extrapolate the data to a more clinically relevant measurement, it is necessary to apply a multiplication factor.

When utilizing a specific type of counting chamber, such as the one used for red blood cell counts, the convention is to multiply the cell count obtained in the counted area by 10,000 to convert it to the normal volume reporting for blood cells (typically expressed per microliter). This factor accounts for the dilution and the precise volume that was analyzed, allowing healthcare providers to obtain accurate and clinically useful results from the small sample that was examined.