Fig. 5. Soft agarose colony assay of parental P19 cells, the clone transfected with empty vector (Mock), and Evi1-transfected P19 cells (clones D2 and D5). A, numbers of colony formation for the parental P19 cells and transformants. Columns, numbers of colonies in each dish; bars, SD. B, micrography of wild-type P19 cells (Ba), wild-type P19 cells 4 days after RA treatment (day 4; Bb), vector-transformant P19 clone (mock; Bc), and Evi1-transformant clones D2 (Bd) grown in the soft agarose after 10 days. C, growth curve of control P19 cells, vector-transfected cells (mock), and Evi1-transfected clones (D2 and D5). Cells (1 x 104 cells/ml) were seeded in 2 ml of culture medium in individual wells of six-well plates. At each indicated time point, cell viability was determined. Data points, mean cell numbers per triplicate wells, plotted against the number of days after seeding; bars, SD. , P19; , mock; , D2; , D5.