Flow cytometry. Cells expressing the surface markers CD4, CD8, and CD3 are labeled in a direct ...

Flow cytometry. Cells expressing the surface markers CD4, CD8, and CD3 are labeled in a direct immunofluorescent technique with an antibody labeled with a fluorochrome. Anti-CD3 is labeled green with fluorescein isothiocyanate, anti-CD4 is labeled red with Texas Red, and anti-CD8 is labeled orange with phycoeryrthrin. Cells are processed single file, passed through an excitation wavelength and a detector  measures the amount of light at each emission wavelength. Also measured are forward scatter for cell size and side scatter for cell granularity.