Spatial structure of chromatin in hybrid cells produced by laser induced fusion studied by optical microscopy

In this article we describe a combined system that uses optical tweezers to bring two living cells into contact and optical scalpel to punctuate their membranes at the contact point. This process initiates a fusion of both cells into one hybrid cell containing two nuclei. If the fusion product is viable, these nuclei tend to mix together. The spatial distribution of the nuclear material in the resulting hybrid nucleus is studied by analysis of positions of FISH (fluorescent hybridization in situ) signals of specific genetic loci in automated fluorescence microscope (high resolution cytometer). The obtained results are compared to the signals distribution of FISH in the original cells.