Representative 2-D gel analysis of membrane and soluble protein preparations from Sod2^+/+, Sod2^–/–, and Euk-189–treated Sod2^–/– red cells. Membrane (200 μg) or soluble red cell protein (400 μg) was separated by 2-D gel electrophoresis. Sod2^+/+ red cell samples were obtained from serially phlebotomized animals (in order to induce reticulocytosis similar to that seen in Sod2^–/– samples). Each sample was prepared from pooled red cells obtained from 5 donor animals.