Agilent QuadriTest CD3 FITC/CD8 PE/CD45 PerCP/CD4 APC Kit is a cocktail of four-color fluorochrome-conjugated antibody reagent for use with Agilent NovoCyte flow cytometers or other suitable flow cytometer systems (like BD FACSCanto II). This reagent is intended to identify and determine the percentages and absolute counts of mature human T lymphocytes (CD3+), suppressor/cytotoxic (CD3+CD8+) T-lymphocyte subsets, and helper/inducer (CD3+CD4+) T-lymphocyte subsets in erythrocyte lysed peripheral blood samples. The results are used in the immunological assessment of normal individuals, and patients having or suspected of having immune deficiency. This reagent is intended for laboratory professional use as a quantitative and semi-quantitative flow cytometric assay. Interpretation of results must be made within the context of the patient’s clinical history and other diagnostic tests by a certified professional.