Figure 3

Temperature, serum and cell density effects on Cre-mediated recombination. (A) Transduction of cell-permeant Cre is inhibited at 4°C. Tex.loxp.EG cells were treated for 2 hours with increasing concentrations of the indicated enzymes at 4 or 37°C and the cells were processed and analyzed for Cre-mediated recombination as described in Figure 1. (B) Effect of serum on Cre-mediated recombination. Tex.loxp.EGFP cells were treated for 2 hours with 2 μM HNC or with 5 μM HC in the presence of increasing concentrations of fetal bovine serum (FBS) or normal mouse serum (MS) and analyzed for Cre-mediated recombination as described in Figure 1. The extent of recombination (percent GFP positive cells) was normalized to cells treated in the absence of serum. (B) Effect of cell density on Cre-mediated recombination. Increasing concentrations of Tex.loxp.EGFP cells were treated for 2 hours with 2 μM HNC and were analyzed for Cre-mediated recombination as described in Figure 1.