CFSE-labeled splenic B cells from Balb/c wild-type mice, and Balb/c mice over-expressing Bcl-2, due to insertion of a Bcl-2 TG, were stimulated for 5 days with BCR-L + IL-4 ± BAFF. Cultures were harvested following the addition of standardization beads to each well, fixed and analyzed by flow cytometry. (A) Shown are overlays of CFSE fluorescence within the viable-gated cells recovered from each set of congenic cultures, stimulated under the indicated conditions. (Results representative of two identical experiments). (B) Bcl-2 TG/WT (wild-type) ratio for total viable cell recovery within each division subset. Total viable cell recovery was computed, with the use of Count-bright standardization beads, from each of 6 replicates. A ratio was obtained by dividing mean value for Bcl-2 TG cultures by mean value for WT cultures in a representative experiment.