On the validity of Rayleigh–Gans–Debye type approximations in red blood cell size determination

The validity of the Rayleigh-Gans-Debye (RGD) approximation for the size determination of a soft prolate spheroidal scatterer has been examined. Calculations have been carried out for the volume range 30–100 µm3 and for aspect ratios ranging from 1.1 to 4.0. Particular attention has been paid to size determination of a red blood cell (RBC) in a flow cytometric arrangement. The applicability of the RGD approximation has been compared with its two modified forms and also with the WKB approximation.