In vitro antiproliferation determined by the cell-counting assay. Cells were seeded in T-flasks at 100 000 cells/mL and treated with 22-20, 20-22, v-mab, e-mab, or a combination of v-mab and e-mab at the indicated concentrations. Viable cell densities (VCD) were determined daily by flow cytometry using Guava Viacount. On day 3, cultures were split 1:2 to maintain logarithmic growth over the course of the assay. The data are plotted as the VCD corresponding to the undiluted culture. (A) Ramos. (B) Raji. (C) Daudi. (D) Dose-response curves generated from cell counts at day 5. Raji cells were treated with various concentrations of 22-20, 20-22, or v-mab + e-mab, and the percentage of untreated cells was plotted versus mAb concentration.