FIG. 2.

Colony forming unit (CFU) frequency can differ between cell lines and with passaging. This corresponds with a decrease in proliferation potential and an increase in cell passage. (A) Percent CFUs were determined by dividing the number of colonies detected by the number of cells plated for cells from PCBM1641 (black) and PCBM1632 (white) at P3, P5, and P7 as described in Materials and Methods. Error bars represent standard deviation; n=3. Asterisk indicates significant difference (p<0.014) between both donors at that passage, marked with a horizontal bar. Significance was also seen within both donors at P3 versus P5, P5 versus P7, and P3 versus P7 (p<0.038). (B, C) Percent confluence as measured by the Incucyte Live Cell Imager for PCBM 1641 (B) and PCBM1632 (C) as a function of time. Error bars represent standard deviation; n=4. P, passage.