A novel method for measuring the erythrocyte deformability, under oscillatory shear stress

A novel apparatus for detecting a subtle decrease in erythrocyte deformability was developed. The oscillatory shape change of erythrocytes was monitored under an oscillatory shear stress (modulating the oscillation frequency in the range of 9-90 dyn/cm2). The ellipsoidal deformation of intact erythrocytes perfectly followed the oscillatory force of up to about 2 Hz, but the diamide-treated cells showed a phase difference of the oscillatory deformation at 1.7 Hz.