Positive identification of human leukaemic cells with scanning immuno-electron microscopy, using antibody coated polystyrene (latex) beads as markers.

Scanning immuno-electron microscopic labelling techniques were successfully used to identify a variety of leukaemia-lymphoma cells. Anti-T, -B and -common type acute lymphoblastic leukaemia (ALL) antisera were covalently conjugated to polystyrene latex spheres by means of glutaraldehyde. Peripheral blood mononuclear cells obtained from healthy individuals and from patients with T-type ALL, B-type chronic lymphocytic leukaemia (CLL), acute and chronic non-lymphoblastic leukaemias (ANLL) and cultured leukaemia-lymphoma cells were incubated with the above antisera-latex conjugates. Positively labelled cells were easily identified by the presence of latex spheres on their surfaces. Cross reactivity of the antisera used and non-specific attachment of the markers were infrequently encountered. The results of this study confirm earlier scanning electron microscopic reports indicating that different leukaemic cells have characteristic surface features and show that scanning immuno-electron microscopy (SIEM) can readily be applied to the study of human leukaemic cells.