Calbryte(TM)-520L, potassium salt

The intracellular calcium flux assay is a widely used method in monitoring signal transduction pathways and high throughput screening of G protein-coupled receptors (GPCRs) and calcium channel targets. Followed by Fluo-3 being introduced in 1989, Fluo-4, Fluo-8 and Cal-520 were later developed with improved signal/background ratio, and became the widely used Ca2+ indicators for confocal microscopy, flow cytometry and high throughput screening applications. Calbryte 520L has low affinity to calcium ion with Kd ~90 uM. Calbryte 520L produces bright fluorescence signal in the presence of calcium ion in high concentration. It has the identical excitation and emission wavelength as Fluo-4, thus the same Fluo-4 assay settings can be readily applied to Calbryte 520L-based calcium assays.