Analysis for markers of hematopoietic differentiation. Ethidium bromide–stained gels of RT-PCR amplification using various marker genes of hematopoietic differentiation. RNA was extracted from EBs derived from WT ES cells (WT) and from 2 different G6pdΔ ES cell lines (G6pdΔ1 and G6pdΔ2). Numbers referring to the days of EB development are shown at the top of the figure. Amplified Hprt is shown as a positive control.