AbstractThe distribution of 2,4‐dinitrophenyl (DNP) groups on Thy‐1 positive epidermal cellsin vivoafter 2,4‐dinitrochlorobenzene (DNCB) was painted on the skin surface of C3H/He mice was examined. Epidermal cell suspensions (EC) derived from trypsin‐separated mouse ear skin painted with DNCB were double‐stained for DNP groups and Thy‐1 protein using FITC‐anti‐DNP antibody, biotinylated anti‐mouse Thy‐1,2 monoclonal antibody, and phyco‐erythrin conjugated avidin. There were on the average 1.7% Thy‐1+ECs; DNP groups were detectable on 77.8% of them when the specimen was treated with anti‐DNP followed by anti‐Thy‐1,2 incubation. The incidence of Thy‐1,2+EC with DNP groups decreased when cells were treated with these antibodies in the reverse order. The significance of these findings is discussed in relationship to th