Though the optics of red blood cells as well as whole blood has been studie
d extensively, an effective scattering phase function for whole blood is st
ill needed. The interference of waves scattered by neighbouring cells canno
t be neglected in highly concentrated suspensions such as whole blood. As a
result, the phase function valid for single erythrocytes may fail to descr
ibe a single scattering process in whole blood with physiological haematocr
it (Hct approximate to 0.4). In this study we compared the results obtained
in goniophotometric measurements of blood samples with the results of angl
e-resolved Monte Carlo simulations. The results show that a Henyey-Greenste
in phase function with an anisotropy factor of 0.972 is an adequate approxi
mation for the effective scattering phase function of whole blood with high
haematocrit at a wavelength of 514 nm.