Growth of STI571-resistant and nonresistant cells.

(A) Growth of STI571-resistant and nonresistant Ba/F3.p210 cells. Diamonds represent nonresistant Ba/F3.p210 cells cultured in the presence of DMSO and harvested and counted by trypan blue exclusion with the use of a hemacytometer at the designated time points. Squares represent STI571-resistant Ba/F3.p210 cells cultured in the presence of 1 μmol/L STI571 and harvested and counted by trypan blue exclusion with the use of a hemacytometer at the designated time points. Triangles represent nonresistant Ba/F3.p210 cells cultured in the presence of 1 μmol/L STI571 and harvested and counted by trypan blue exclusion with the use of a hemacytometer at the designated time points. Cell number was determined by counting viable cells. (B) Growth of STI571-resistant and nonresistant K562 cells. Diamonds represent nonresistant K562 cells cultured in the presence of DMSO and harvested and counted by trypan blue exclusion with the use of a hemacytometer at the designated time points. Squares represent STI571-resistant K562 cells cultured in the presence of 0.5 μmol/L STI571 and harvested and counted by trypan blue exclusion with the use of a hemacytometer at the designated time points. Triangles represent nonresistant K562 cells cultured in the presence of 0.5 μmol/L STI571 and harvested and counted by trypan blue exclusion with the use of a hemacytometer at the designated time points. Cell number was determined by counting viable cells.