Domain specificity of 4 antivimentin antibodies and their affinity for human T-cell surface. (A) Head, rod, and tail domains of human vimentin, with apparent molecular weights of 12, 37, and 8 kDa, respectively, are shown with their antibody specificity. (B) Cell-size scatter of T cells treated with an anti-Fas antibody for 18 hours. Regions corresponding to living, apoptotic, and late apoptotic cells are identified according to cell size (FS) and granularity (SS). (C) Cells were incubated with indicated antivimentin antibodies or an isotype control (shadow area) and then incubated with the corresponding FITC-conjugated secondary antibodies. A minimum of 15 000 cells per gate were analyzed by flow cytometry. (D) Cells were stained with the antivimentin antibody V4630, incubated with the secondary FITC-coupled antigoat antibody, and analyzed by flow cytometry. The mean ± SEM fluorescent channel of early apoptotic or late apoptotic cells from 3 independent experiments is shown.