Scanning flow cytometry for individual particle analysis

With this work we review the development of theoretical and experimental aspects of the scanning flow cytometry (SFC). The optical and hydrodynamic systems of the SFC provide the measurement of fluorescence and light scattering of individual particles with a typical rate up to 500 particles/s. In addition the optical system of the SFC has the capability of individual particle analysis beyond that of an ordinary flow cytometry. The SFC measures an entire angular dependency of light scattering intensity (flying light scattering indicatrix, FLSI) over angles ranging from 5 degrees to 120 degrees. The fluorescence collection efficiency of the SFC approaches 1/3 of a sphere. Moreover, the optical system of the SFC provides the measurement of fluorescence in a time-resolved mode on a microsecond time scale. The processing of the output data in light scattering is based on a parametric solution of the inverse light-scattering problem, the FLSI method. The FLSI method allows the determination of size and refractive index of spherically modeled particles over a range of diameters from 0.9 to 15 mu m and a range of refractive indexes from 1.37 to 1.60. The performance of the SFC in different applications has been demonstrated. (C) 2000 American Institute of Physics. [S0034-6748(00)04801-2].