Effect of growth/viability factor deprivation on FDC-P1 transfectants expressing versus not expressing mcl-1. mcl-1 transfectants (S3-CMVmcl-1 and S8-CMVmcl-1) and vector-only clones (V1-CMVneo and V2-CMVneo) were transferred from transfectant growth medium (containing 10% FBS and 10% WEHI-3b conditioned medium) to growth factor-depleted medium (containing 1% FBS and lacking a source of IL-3, see Materials and Methods) at an inoculum density of 5 × 105 cells/mL. Viability was assayed at the indicated times using trypan blue dye exclusion. The values shown are the mean ± SD of three independent experiments. The average total cell number (×105) in the mcl-1 transfectants was 6.7, 8.0, 7.9, and 7.6 on days 1 through 4, respectively. The average total cell number (×105) in the vector-only clones was 8.9, 9.5, 9.6, and 10.0 on days 1 through 4, respectively. Viability in growth factor-containing medium was greater than 96%.
