cytotropic antibody test

cy·to·tro·pic an·ti·bod·y test

a rosette test for macrophage cytotropic antibody: monolayers of macrophages are exposed first to antibody cytotropic for macrophages, then to the antigen (for which the antibody is specific), and indicator sheep erythrocytes; if the antibody is specific for sheep erythrocytes, the latter will form a rosette around the macrophages directly, but if not, and the antigen is soluble, the antigen must be coupled to the sheep erythrocytes by an agent such as bis-diazotized benzidine.