MCD 8 (CD8) / B-B10 (CD25)  dual combination is a direct immunofluorescence reagent used for the detection of mature T lymphocytes in whole blood (either lysed or non-lysed) using flow cytometry. In the diagnosis of T-cells, the IL-2 receptor is expressed on activated cells including T cells. It is
also present on a subset of thymocytes, HTLV-1 transformed T and B cells, EBV transformed B cells, myeloid precursors and oligodendrocytes. IL-2 induces the expression of the CD25 subunit on NK cells.