Localized mapping of bioparticle size distribution using Angular Scattering Microscopy

Abstract

A new and simple optical protocol for quantitative particle localization and sizing based on Mie theory is simulated and experimentally implemented. The technique, referred to as Angular Scatter Microscopy (ASM), selectively highlights signals from particular size distribution at each point on the sample using two annular rings displayed by a multimedia projector that differentiate high from low scattering frequencies. The image quotient of the corresponding two images which we call Angular Scattering Ratio (ASR), converts scattering intensity to particle size. This effectively reveals the location of scatterers across the sample and quantifies their sizes by virtue of their ASR value. The ease with which the illumination patterns are generated makes the system viable for dynamic local particle sizing.