Elastic and inelastic light scattering in flow cytometry.

A review of the fundamental aspects of elastic light scattering suggests that information about the shape and internal structure may best be obtained from signals measured in the backscattering directions. Size information can be most readily extracted from forward scattering signals. Spectral analysis of scattered signals with incident white light is a subject that merits further study. Signals from cells that have been stained with fluorescent dyes are proportional to dye content in the usual flow-cytometric configuration except in the case of dense, strongly anisometric structures such as sperm cells. The recent discovery that Raman signals from molecules adsorbed on small silver particles are strongly enhanced suggests the possibility of utilizing this effect for identification of molecular species inside biological cells.