Effect of red blood cells aggregation on scattering coefficient

Red blood cells (RBCs) suspended in plasma aggregate. This paper presents a method to determine the scattering coefficient of RBC suspensions at 632nm wavelength. Blood was obtained from healthy donors. The intensity of the coherent component of scattered light from the suspension located in a wedge-shaped container was measured during 35 min at a sample thickness from 127 to 547 mu m, at hematocrits 0.01 to 0.04. It is shown that the scattering coefficient linearly decreases with time at the early stages of RBC aggregation. The time dependence of the coefficient becomes nonlinear when the early aggregation is completed. The duration of the early phase of RBC aggregation decreases as hematocrit increases. At very small hematocrits (Ht <= 0.01) the scattering coefficient is independent of the thickness of the sample. The effect of the sample thickness on the scattering at higher hematocrits has been demonstrated