Representative trajectories of DIDS-biotin–labeled band 3 on normal and mutant intact human erythrocytes. After labeling with DIDS-biotin conjugate, the diffusion of the labeled band 3 was imaged for 100 consecutive frames at 120 frames/s on fixed normal, unfixed normal, HS, HPP, HE, HHy, and SAO erythrocytes. Because most of these cell types have multiple populations of band 3, the trajectory of only the most abundant population is displayed (percent of total band 3 is indicated in parentheses).