A possible correlation of electro-optic changes with the deformability of erythrocytes.

A novel electro-optical technique for deformability measurement is described. This method is faster and more convenient than "standard" procedures. Erythrocytes (RBC, 10(6) cells/mL suspended in isotonic sucrose 10%, ionic strength 10(-4) M/L, pH 6.5) are ordered in an electric field (E = 10(4) Vp-p/m, v = 10(3) Hz) following the field direction, as a result of an induced electric dipole moment. After the switching off of the electric field, a certain time is required for the electro-optic effect to subside. Under the action of thermal motion, the suspended erythrocytes virtually return to their initial unordered state. The decay time (return time) is the investigated parameter. Results show that if erythrocyte deformability is reduced, the return time is longer than in control RBC. Suspensions of erythrocytes with reduced deformability, achieved by treatment with glutaraldehyde at concentrations ranging from 10(-8) to 10(-1) M/L, are measured. The suggested electro-optic method has good precision and requires a very small quantity of blood (about 0.1 mL), which makes it potentially useful in clinical practice.