Flow cytometry is an innovative technology by means of which different cell characteristics are simultaneously analyzed on a single cell basis. This is achieved through hydrodynamic focusing of cells that pass aligned one by one and they are illuminated by a laser beam. The interaction of the cells with the laser beam generates signals of two different types: those generated by dispersed light (FSC/SSC),  which mainly reflects the size of the cell and its  internal complexity, and those related to the emission of light by the fluorochromes  present in/on the cell. These signals become electric impulses which are amplified and registered as digital signals to be processed by a computer. When the reagents are added to the sample, the mixture of fluorochrome-labeled antibodies present in the reagents bind specifically to the antigens they are directed against, allowing the detection by flow cytometry of the different cell subsets. The erythrocyte population, which could hinder the detection of the target population, is eliminated by the use of a red blood cell lysing solution previous to acquire the sample on the cytometer.