(A) Expression of Bcl-2 and Bax protein in B-CLL cells from L-206, L-194, and L-156 patients. Cells were incubated in RAM-Ig–coated 24-well plates with medium, anti-IgM, or anti-IgM plus IOR-T1. Bcl-2 and Bax proteins were determined by flow cytometry after 16 hours. The solid line indicates Bcl-2 or Bax staining and the dotted line represents background control cells staining with nonspecific hamster IgG or rabbit IgG. Specific MFI (after the subtraction of background MFI) is in the right corner of each panel. (B) Negative control for Bcl-2 staining. The dotted and solid lines indicate background and Bcl-2 staining in Daudi cell line, respectively. (C) Specificity of the Bax antibody. Two different B-CLL cells were stained with anti-Bax antibodies that had been blocked with the specific peptide (AA 43-61; dashed line). The dotted and solid lines indicate background control and Bax staining, respectively. The x-axis corresponds to logarithmic fluorescence intensity and the y-axis corresponds to cell number.