Triple combination Isotype Control MCG2a (IgG2a FITC)  /  MCG1 (IgG1 R-PE)  / MCG1 (IgG1CyQ) is a 3-color direct immuno-fluorescence reagent for use as a negative control in flow cytometric immunophenotyping of erythrocyte-lysed whole blood (LWB). This combination is used to estimate the amount of non-antigen-specific antibody binding (non-specific staining) present, particularly that caused by Fc receptors .