Calcium pump Calcium pump Calcium pumps are a family of ion transporters found in the cell membrane of all animal cells. They are responsible for the active transport of calcium out of the cell for the maintenance of the steep Ca electrochemical gradient across the cell membrane. Calcium pumps play a crucial role in proper cell signalling by keeping the intracellular calcium concentration roughly 10,000 times lower than the extracellular concentration. Failure to do so is one cause of muscle cramps. The plasma membrane Ca ATPase and the sodium-calcium exchanger are together the main regulators of intracellular Ca concentrations. Ca has many
Calcium imaging dye in all cells or selectively in certain cellular subtypes. GECIs have been used in the studies of neuron, T-cell, cardiomyocyte, etc. Regardless of the type of indicator used the imaging procedure is generally very similar. Isolated cells loaded with an indicator or expressing it in the case of GECI, can be viewed using a fluorescence microscope and captured by a Scientific CMOS (sCMOS) camera or CCD camera. Confocal and two-photon microscopes provide improved sectioning ability so that calcium signals can be resolved in micro domains or (for example) synaptic boutons. Images are analyzed by measuring fluorescence intensity changes for