Analysis of sub-micron spherical particles using scanning flow cytometry

Determination of individual sub-micron particle size and refractive index w as performed with a parametric solution of the inverse light-scattering pro blem. The parametric solution is based on approximating equations that rela te the particle characteristics to the parameters of the indicatrix tan ang ular dependence of light-scattering intensity). The approximation equations allow real-time calculation of particle size and refractive index ranging from 0.5 to 1.5 mum and from 1.37 to 1.69, respectively. The applicability of the parametric solution was demonstrated with the analysis of polystyren e particles, the indicatrices of which were measured using scanning flow cy tometry. We measured samples of monodisperse polystyrene particles with dia meters of 0.6 and 0.83 mum. The measured indicatrices were processed with t he parametric solution and best-fit regression to the Mie theory. The deter mined particle parameters were in a good agreement with the specifications.