Rates of in vitro synthesis of radiolabeled γ and β chains made in a cell-free transcription/
translation system were similar, but expressed globin chains were unstable. The addition of
unlabeled β or γ chains at the start of chain synthesis generated radiolabeled β 4 or γ 2 and
γ 4 chains, respectively. If unlabeled α-globin chains were added at the start of chain
synthesis, then approximately equal amounts of radiolabeled αβ or αγ bands were
generated. If unlabeled Hb A or Hb F was added to reactions containing radiolabeled αβ or …