Abstract: The invention relates to a method and system for characterizing particles using a flow cytometer comprising detecting radiated light from the particles using two or more detectors positioned to allow for the detection in two or more angular directions and generating a waveform, as a digital representation for the detected radiated light for each of said angulation direction. The waveforms are transformed using one or more basis functions to obtain one or more coefficients characterizing the waveform. The one or more coefficients characterizing the waveform preferably correspond to properties of the particle(s), thereby enabling analysis of physical properties of the particles (such as size, shape, refractive index) or biological properties of the particles (such as cell type, cell cycle state or localization or distribution of molecules within the cell and/or on the cell surface). In preferred embodiments the method and system are used for a label-free sorting of particles, in particular biological cells.

Abstract: The invention relates to a method and system for characterizing particles using a flow cytometer comprising generating a waveform, as a digital representation of detected radiated light, and transforming said waveform using one or more basis functions and obtaining one or more coefficients characterizing the waveform. The one or more coefficients characterizing the waveform preferably correspond to particular properties of the particle(s), thereby enabling analysis of physical properties of the particles (such as size or shape) or biological properties of the particles, such as cell type, localization and/or distribution of molecules within the cell and/or on the cell surface, structural elements of the cell such as the nucleus or the cytoskeleton, antibody or antibody-fragment binding to the cell or cell morphology. Preferred embodiments of the invention relate to methods and systems in which the waveform is transformed by a wavelet transformation or Fourier transformation.