Live-Cell Imaging of Peroxisomal Calcium Levels and Dynamics

Calcium (Ca²⁺) is an intracellular messenger that plays an essential role in a variety of cellular processes ranging from early embryonic events to muscle contraction and neuron excitability. Measurement of cytosolic, endoplasmic reticulum (ER), and mitochondrial Ca²⁺ has contributed immensely to our understanding of cellular physiology. Here we describe the measurement of peroxisomal Ca²⁺ using ratiometric Ca²⁺ sensors, enabling measurement of absolute Ca²⁺ concentration and its dynamics in living cells.