Scanning electron micrographs of peripheral RBCs in a normal subject and the homozygous patient with total protein 4.1 deficiency. The patient was splenectomized in 1979. RBCs were fixed with 1% glutaraldehyde solution immediately after blood was drawn and transferred at 4°C. Striking poikilocytosis and anisocytosis were noted on the background of elliptocytosis in the 4.1 (−) Madrid case (B), compared with normal discocytes in a representative normal subject (A). Original magnification × 1,500.