Fig. 6. Effects of noggin on human ES cells. (A) Area of differentiation in ES cell colony; (B) noggin-treated cells. (C) Cells from a colony similar to B after replating onto fresh feeder cell layer. Bar, 50 µm. (D) Proportion of GCTM-2-positive cells in human ES cultures after 5 days of growth under control conditions or in the presence of 200 ng/ml noggin. (E) RT-PCR analysis of gene expression in human ES cultures after 5 days of growth under control conditions or in the presence of 200 ng/ml noggin.