Cytologic changes during primitive erythroid maturation. Giemsa-stained cytospin preparations of FACS-sorted E8.5 EryP from dispersed ε-globin-H2B-GFP embryos^12,42  or peripheral blood from wild-type embryos at E9.5 to E14.5.¹³  Panels E9.5 to 14.5 were taken from Fraser et al.¹³  Scale bar represents 20 μm.