Wide-angle light-scattering differentiation of organelle-size particle distributions in whole cells.

A finite-difference time-domain (FDTD) method is used to study the multiple scattering from many organelle-size particles distributed in a biological cell. Conventional flow cytometry, where the small-angle forward scatter (FSC) intensity and side scatter (SSC) intensity are used for cell characterizations, may have difficulties to differentiate the organelle distributions in biological cells. Based on the FDTD simulations, a light-scattering methodology is proposed here to overcome such a problem. This method differentiates the dense and sparse distributions of organelle-size particles in a cell, by counting the peak numbers in both large-angle FSC and wide-angle SSC, with the multiple scattering effects being considered. Implemented with a wide-angle microfluidic cytometer, the approach demonstrated in this theoretical study may find potential applications in clinics for label-free cell physiological study.