Immunoblot comparisons of CPP32 and Bcl-2 in normal GC and MZ B cells. GC and MZ B cells were obtained by FACS of human tonsilar B cells. Lysates were prepared and normalized for total protein content (25 μg per lane), and a Western blot was prepared. The blot was sequentially probed with antisera specific for CPP32 (lanes 1 through 4), Bcl-2 (lanes 5 and 6), and F₁ -β-ATPase (lanes 7 and 8). Lanes 1 and 2 represent recombinant CPP32 protein (50 ng) that was either treated (+; lane 1) or untreated (−; lane 2) with granzyme B (included as a positive control).