HPLC assays identify a new peak in peripheral primitive erythroid cells from ΔEyΔβh1 embryos. (A) HPLC of cell lysate of e10.5 circulating blood from wild-type D/S embryo shows identified elution peaks from the wild-type D and S alleles. Ey1 is from the S allele, and Ey2 is from the D allele. The βh1 peak includes protein from D and S, and alpha and zeta are α-like globin chains. (B) HPLC of cell lysate of d10.5 circulating blood from ΔEyΔβh1/S embryo. Identified elution peaks include alpha and zeta and from the S allele, Ey1, and βh1. The Ey2 peak from D is missing. A peak represents β-major and β-minor (beta), and a new peak (?) represents a novel β-like globin chain. (C) HPLC of cell lysate of mixed e10.5 circulating blood from wild-type D/S and ΔEyΔβh1/S embryos shows that the new peak (?) is distinguished from Ey1 and Ey2.