Deformation and fragmentation of human red blood cells in turbulent shear flow.

By means of glutaraldehyde fixation, human erythrocytes are "frozen" while suspended in turbulent shear flow. As the shearing is increased in steps from 100 to 2,500 dyn/cm2, the deformed cells evolve gradually toward a smooth ellipsoidal shape. At stresses above 2,500 dyn/cm2, approximately, fragmentation of the cells occurs with a concomitant increase in free hemoglobin content of the suspending medium. The photographic evidence suggests that the cells rupture in tension in the bulk flow.