Kinetics of β-H1 and β-major globin expression. Analysis of RNA extracted from EBs derived from WT (□) and G6pdΔ (▪) ES cells at different days of differentiation. (A) The ratio of bands specific for β-H1 globin to bands specific for Hprt, produced by semiquantitative RT-PCR, plotted against the days of differentiation. (B) Ratio of bands specific for adult globin β-major to bands specific for Hprt, produced by semiquantitative RT-PCR, plotted against days of differentiation. Data represent the average of three independent experiments (mean ± SD).