MULTI-MODAL IMAGING OF CYTOSOLIC AND MITOCHONDRIAL CA2+

♣These authors contributed equally to this work Cultured HeLa cells were loaded with Ca2+ sensitive fluorescent probes targeted to the mitochondria (rhod-2), and to the cytosol (fluo-3 and fura-2). We performed fluorescence imaging on these live cells under software control and enhanced the optical sectioning off-line by applying a nearest-neighbor deconvolution algorithm based on a directly estimated point-spread function (PSF). The different dynamics of cytosolic and mitochondrial Ca2+ signals evoked the UV flash photolysis of a photo-labile Ca2+ chelator could be distinguished clearly, with sub-micron resolution. The results indicate that this approach is suitable for the analysis of the interactions and cross-talks between different signaling pathways