The AQUIOS PLG Panel is for use on the AQUIOS CL flow cytometer system. The reagent combines two fluorescent-labeled monoclonal antibodies in a single reagent formulation. It is intended “For In Vitro Diagnostic Use” for the identification and enumeration of CD4+ absolute cell count and CD4+ lymphocyte percentage when used in combination with AQUIOS Flow-Count Fluorospheres as a single platform measurement. This reagent is indicated for use in the immunologic assessment of patients having, or suspected of having, immune deficiency.