Osmotic response of lymphocytes measured by means of forward light scattering: theoretical considerations

Recent data provide solid experimental evidence that increase in cell size of human lymphocytes, caused by osmotic stress, is not directly proportional to forward scattering intensity but rather is inversely proportional. Here, we provide arguments that this phenomenon can be quantitatively explained by means of a model based on a modified Rayleigh-Debye-Gans theory. As a consequence, the current view that forward scattering intensities can be used as a measure of gross cell size needs to be reconsidered. In addition, we postulate that structural changes of the cytoplasm, imposed by an osmotic stress, reflect corresponding changes in the nucleus.