Optical tweezer for probing erythrocyte membrane deformability

TL;DR

This paper introduces an optical tweezer method to measure erythrocyte membrane deformability by analyzing the rotation speed of crenated cells under polarized light, linking cell rigidity to environmental factors.

Contribution

It presents a novel optical trapping technique to quantify erythrocyte membrane deformability through rotation speed analysis of crenated cells.

Findings

Increased membrane rigidity correlates with higher rotation speeds.

Calcium ion adsorption enhances erythrocyte membrane stiffness.

The method provides a non-invasive way to assess cell deformability.

Abstract

We report that the average rotation speed of optically trapped crenated erythrocytes is direct signature of their membrane deformability. When placed in hypertonic buffer, discocytic erythrocytes are subjected to crenation. The deformation of cells brings in chirality and asymmetry in shape that make them rotate under the scattering force of a linearly polarized optical trap. A change in the deformability of the erythrocytes, due to any internal or environmental factor, affects the rotation speed of the trapped crenated cells. Here we show how the increment in erythrocyte membrane rigidity with adsorption of $Ca^{++}$ ions can be exhibited through this approach.