AbstractA novel technique employed in preparing slides used for immunofluorescence staining of human tumor antigens with human anti‐cancer monoclonal antibodies is described. The anchorage of the cancer cells to the plastic substratum is used as a basis in eliminating cell fixation by physical and chemical procedures. In this method, the bottoms of the tissue culture flasks with the adherent A431 cell line, a carcinoma of the vulva, were cut into slides of 2 × 6 cm. This antigen‐positive target cell was then reacted with the VLN3G2 monoclonal IgG antibody and with the fluorescein‐labeled F(ab′)2of goat anti‐human IgG. Most A431 cells demonstrated intense fluorescence staining while others exhibited diffuse and often discontinuous membrane staining with the antibodies. In summary, this simplistic technique can be applied for the rapid detection of antigens displayed by the adherent tumor