Cytofluorometric analysis of accelerated spontaneous apoptosis affecting post-BMT T cells in short-term cultures. PBL from BMT patients and their donors were tested for apoptosis either directly after harvesting (ex vivo) or after an 18-hour incubation in culture medium. (A) A typical experiment performed with the cells of UPN 315 showing the percentages of cells with low ▵Ψm (DiOC₆(3)^low). (B) Percentages of hypodiploid cells detected in the same culture conditions by staining ethanol-permeabilized lymphocytes from UPN 294 with propidium iodide (linear scales are shown).