The effects of rapamycin and dexamethasone on growth and apoptosis in freshly isolated bone marrow plasma cells from patients with MM. (A) Purified CD138⁺ plasma cells from 8 patients with MM were cultured for 48 hours in the presence of rapamycin and/or dexamethasone followed by addition of resazurin to a final concentration of 10%. After 3 hours of incubation the wells were analyzed by using the resazurin assay, and fluorometry and results are presented as mean ± SD where n = 3. (B) Isolated MM cells from patient 3 were cultured for 48 hours in the presence of rapamycin and/or dexamethasone followed by PI staining of cell nuclei and flow cytometric analysis according to Vindelöv.³⁸  The indicated hypodiploid population reflects the amount of apoptosis in each sample.