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Updated: Aug 16, 2026

Simultaneous Measurement of Mitochondrial Calcium and Mitochondrial Membrane Potential in Live Cells by Fluorescent Microscopy
Published on: January 24, 2017
Mitochondria and calcium signaling
1Buck Institute for Age Research, Redwood Boulevard, Novato, CA 94945, USA. dnicholls@buckinstitute.org
Abstract:
The kinetic properties for the uptake, storage and release of Ca2+ from isolated mitochondria accurately predict the behaviour of the organelles within the intact cell. While the steady-state cycling of Ca2+ across the inner membrane between independent uptake and efflux pathways seems at first sight to be symmetrical, the distinctive kinetics of the uniporter, which is highly dependent on external free Ca2+ concentration and the efflux pathway, whose activity is clamped over a wide range of total matrix Ca2+ by the solubility of the calcium phosphate complex provide a mechanism whereby mitochondria reversibly sequester transient elevations in cytoplasmic Ca2+. Under non-stimulated conditions, the same transport processes can regulate matrix Ca2+ concentrations and hence citric acid cycle activity.
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