Different sizes of the protected fragment of βh1-globin mRNA produced by cells with different haplotype origins. RNA samples from Ba/F3 cells treated with 15 nmol/L TSA (Ba/F3-TSA, L), B6SUtA cells treated with 1.0 mmol/L SB (B6SUtA-SB, H), and 11.5-day-old DBA/2 mouse embryonal blood (d11.5 emb) were hybridized with the βh1-globin probe alone (lanes 4, 5, and 6). The same set of RNA samples was hybridized with the ɛ-globin probe alone (lanes 1, 2, and 3).