Mitochondrial Na+/Ca2+ exchange assays.
Here, we describe two complementary assays designed to analyze mitochondrial Na(+)/Ca(2+) exchange activity. In both procedures, the counter ion transport of sodium and calcium ions across the inner membrane of mitochondria is assayed in permeabilized cells preloaded with a mitochondria-selective Na(+) probe, CoroNa-Red, or with a mitochondria-targeted calcium sensor, ratiometric-pericam, respectively. These methods, therefore, do not require a mitochondrial preisolation step, with the native cellular mitochondrial architecture being maintained. Importantly, these methods equilibrate the cytosol with the extracellular milieu to allow control over the extra-mitochondrial ionic environment, while eliminating any possible interference by plasma membrane transporters.
Department of Molecular and Cell Biology, University of California, Berkeley, California 94720;
Raz
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Palty
Varda
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Shoshan-Barmatz
D000818:Animals; D001681:Biological Assay / Q000379:methods*; D002118:Calcium / Q000378:metabolism*; D002460:Cell Line; D002463:Cell Membrane Permeability; D057809:HEK293 Cells; D006801:Humans; D008928:Mitochondria / Q000378:metabolism*; D051336:Mitochondrial Membranes / Q000378:metabolism; D012964:Sodium / Q000378:metabolism*; D013997:Time Factors
D012964:Sodium; D002118:Calcium