Mechanical property analysis of stored red blood cell using optical tweezers

The deformation of human red blood cells subjected to direct stretching by optical tweezers was analyzed. The maximum force exerted by optical tweezers on the cell via a polystyrene microbead 5 μm in diameter was 315 pN. Digital image correlation (DIC) method was introduced to calculate the force and the deformation of the cell for the first time. Force–extension relation curves of the biconcave cell were quantitatively assessed when erythrocytes were stored in Alsever's Solution for 2 days, 5 days, 7 days and 14 days respectively. Experiment results demonstrated that the deformability of red blood cells was impaired with the stored time.