Optical study of the dynamics and deformation of erythrocytes in the flow

Optical study of the dynamics and deformation of erythrocytes in flow was performed by two methods. Cells were trapped and manipulated with laser tweezers. Laser tweezers allow observing the deformation of a single cell or a cell aggregate under various experimental conditions, such as at rest or in flow, and also studying the aggregation of erythrocytes, which is an important process that affects blood rheology. Another method — ektacytometry 3— is based on obtaining information about the microrheological parameters of erythrocytes from diffraction patterns of laser radiation on a diluted suspension of cells in a flow and at rest. This method makes it possible to determine the average shear strain of a whole ensemble that includes many thousands of particles from changes in the diffraction pattern depending on the shear stress applied to the cells. The forces of interaction between two erythrocytes in an aggregate are measured and the cell deformation parameters are determined. The data on erythrocyte deformation obtained by the two methods agree well with each other.