Table 1. Microscopic analysis of myogenin and myosin heavy chain expression. P19 pluripotent stem cells were grown as EBs for 4 days and treated with DMSO, valproic acid (VPA, 0.5 mM), or in combination with RA (10 nM). The cells were then cultured for 5 days without treatment, and stained for myosin heavy chain (MyHC) and myogenin in parallel before microscopic analysis. Untreated cells (Control) were also included.

	Myogenic conversion indicated by MyHC stain (% ± SD)	Myogenic conversion indicated by myogenin stain (% ± SD)
Control	0.66 ± 0.48	0.15 ± 0.02
DMSO + RA	24.51 ± 1.61	20.59 ± 2.23
DMSO	4.02 ± 2.48	3.27 ± 1.48
RA	2.84 ± 0.73	3.56 ± 2.05
VPA	2.88 ± 2.25	2.26 ± 2.23
VPA + RA	17.85 ± 1.07	15.83 ± 0.33