Immunocytochemical detection of AC2 and AC4 stably expressed in HEK 293 cells. A,E, HEK 293 cells transfected with the pCEP4 vector (designated HEK 293) were processed for immunocytochemistry with the AC2 (A) or AC4 (E) antibody as described in Materials and Methods. B, F, HEK 293 cells expressing AC2 or AC4 (designated 293-AC2 or293-AC4) were labeled with the AC2 (B) or AC4 (F) antibody.C, Adsorption of the AC2 antibody with AC2 peptide antigen (PEP) blocked AC2 immunolabeling in HEK 293 cells expressing AC2. D, Cells expressing AC4 did not label with the AC2 antibody. G, Adsorption of the AC4 antibody with AC4 peptide antigen blocked AC4 immunolabeling in HEK 293 cells expressing AC4. H, Cells expressing AC2 did not label with the AC4 antibody. Scale bar, 25 μm.