Lack of Band 3 expression in AE−/− gene-disrupted NZB mice. Lanes A-D illustrate ethidium bromide staining of agarose gel–fractionated PCR products corresponding to the disrupted (A,B, 600 base pairs) or wild-type (C,D, 400 base pairs) AE1 gene sequence using samples of genomic DNA from heterozygous AE+/− (A,C) or homozygous (B,D) AE−/− NZB mice. Lanes E and F illustrate SDS-PAGE analysis of wild-type (E) or AE−/− (F) murine RBC membrane preparations stained for protein with Coomassie Blue. Each track was loaded with approximately 20 μg protein. The position of Band 3, with an apparent molecular mass of 100 kDa, is indicated (→).