Figure 4

Combining the 1 mM thymidine pre-treatment with a 2 mM post-treatment retains high levels of gene repair. Cells were treated with 1 mM thymidine for 24 hours, electroporated with 1 μM EGFP3S/47NT oligo, and recovered in complete medium without thymidine (a and b) or in the presence of 2 mM thymidine (c through f) for 48 hours (a and c) or for 144 hours (b and d-f). At 48 and 72 hours, sample e and f, respectively, were washed 2× with PBS and fresh medium was added that did not contain any thymidine (termed "w/o" for "washed out"); these cells were collected at 144 hours and analyzed by FACS for eGFP fluorescence. Correction efficiency depicts the percentage of live green fluorescent cells in the total number of cells counted (50,000 per sample); means and standard deviations were calculated based on the results of three to four independent experiments. T-tests were performed comparing b to d and e (**p < 0.05).