Mature T cells can be divided into two major types:
- Helper cells
- Suppressor cells (cytotoxic T cells)
The orange labeled MoAbs are specific for the CD3 antigen on T cells, and the green labeled MoAbs are specific for the CD4 antigen on T cells. When a true T-helper cell is analyzed in the flow cytometer, it would emit both colors after it passes through the laser, as illustrated in the image on the right.