Imaging Flow Cytometry
Development of techniques to image single cells and particles in flow cytometry
Optical flow cytometry is a well-established technique to analyze cell populations in laboratory medicine. Cells of the sample under investigation are guided one after the other through a laser beam. They are counted and differentiated according to the intensity of the scattered laser light or by detecting fluorescence from labels bound to cell subgroups of the sample. Accuracy and uncertainty of the technique are mainly determined by the occurrence of coincidences (two or more particles pass the laser beam simultaneously) or by cell agglomerates. Often, these events cannot safely be distinguished from single cells of larger size.
The research project „Imaging Flow Cytometry“ aims at the development of methods to record microscopic images of the cells when passing the optical beam. In this way, morphological information can be gained for each cell. The method offers even the chance to localize sources of fluorescence inside the cells, depending on cell size, spatial resolution and sensitivity of the image acquisition. Moreover, the technique measures the angular pattern of the light scattered by the cells which is then compared to and analyzed by simulations of light scattering. Using both, image and scatter pattern information, rare cells can be counted more precisely. The research is of particular interest for the development of new and advanced reference techniques for cell counting in laboratory medicine.