Expression of transferrin receptors during erythroid maturation.

A monoclonal antibody, F111/2Dl, produced after immunisation of C3H/He mice with the human erythroleukemia cell line, K562, is described. It detects cell surface determinants of similar distribution to those characterised by the OKT-9 monoclonal antibody, which has been shown to identify the transferrin receptor. The F111/2Dl antibody, as well as OKT-9, has been used to investigate the distribution of transferrin receptors during erythroid maturation in normal bone marrow and peripheral blood, and on the K562 cell line during erythroid differentiation, induced in vitro.