Immunofluorescence analysis of Langerhans cells. Langerhans cells were isolated from 6-mm-punch biopsies of uninvolved skin using magnetic CD1a beads. Cells were stained on cytospin preparations using an FITC-labeled CD1a antibody and cell nuclei counterstaining with 7-AAD (DMR microscope equipped with an HCX PL FLUOTAR 40 ×/0.75 non-oil objective lens, DFC-camera, and IM500 V4.0 software; Leica, Wetzlar, Germany).