FIG. 1.

Specificity of lymphocyte intracellular perforin staining. (a) Staining of lymphocytes incubated with PE-labeled antiperforin antibody alone (black) or following preincubation with unlabeled antiperforin (blocking) antibody (gray); (b) staining of NK cells incubated with PE-labeled antiperforin antibody alone (black) or following preincubation with unlabeled antiperforin (blocking) antibody (gray); (c) staining of cytotoxic T lymphocytes incubated with PE-labeled antiperforin antibody alone (black) or following preincubation with unlabeled perforin (blocking) antibody (gray).