Studies on erythrocytes of the homozygous band 3 Neapolis. (A) SDS-PAGE analysis of red-cell membrane proteins. Membrane proteins of red cells were separated by SDS-PAGE⁴¹  and the gel stained by Coomassie blue G. (B) Immunoblotting of band 3. The membrane content of band 3 was determined by immunoblotting, using an anti-band 3 monoclonal antibody. Equivalent amounts of membrane proteins were loaded, based on the GPC content. (C) Immunoblotting of GPA and GPC and CD47. Red-cell membrane content of GPA, GPC, and CD47 was evaluated by immunoblotting, using monospecific antibodies. (D) Scanning electron micrograph of red cells of the proband. (E) Quantitation of anion transport. DIDS-sensitive unidirectional disodium [³⁵S] sulfate uptake in red cells of normal and proband red cells.