RNA was harvested from murine ES cells at 18, 48, and 96 hrs, reverse transcribed to cDNA, and used for RT-PCR reactions. Experiments were performed in triplicate with three independent RNA samples, and showed similar results. Representative gels of (A) cdh1 (33 cycles) following 96 hr treatment, and (B) MEST (33 cycles) following 48 hr treatment are shown. Cycle number was optimized using serial dilutions to prevent saturation. Gel bands were measured by densitometry, averaged and plotted (± SD) relative to 36B4. Significance is indicated by an asterisk (p < 0.05).