Calcium imaging

Calcium imaging is a microscopy technique to optically measure the calcium (Ca) status of an isolated cell, tissue or medium. Calcium imaging takes advantage of calcium indicators, fluorescent molecules that respond to the binding of Ca ions by fluorescence properties. Two main classes of calcium indicators exist: chemical indicators and genetically encoded calcium indicators (GECI). This technique has allowed studies of calcium signalling in a wide variety of cell types, and can be used to measure electrical activity in hundreds of neurons in cell culture, or in living animals during ongoing behavior.