Screen Quest(TM) Fura-2 No Wash Calcium Assay Kit

Calcium flux assays are preferred methods in drug discovery for screening G protein coupled receptors (GPCR). This ratiometric calcium assay kit allows homogeneous measurement of intracellular calcium changes caused by activation of G-protein-coupled receptors or calcium channels. Cells expressing a GPCR of interest that signals through calcium are pre-loaded with Fura-2 AM which can cross cell membrane. Once inside the cell, the lipophilic blocking groups of Fura-2 AM are cleaved by esterases, resulting in a negatively charged fluorescent dye that stays inside cells and its fluorescence wavelength is blue-shifted upon binding to calcium. When cells stimulated with agonists, the receptor signals the release of intracellular calcium, which greatly increase the fluorescence intensity ofFura-2 at the short wavelength. The ratiometric characteristics of Fura-2 make this kit an ideal tool for more accurate measurement of cellular calcium concentration compared to Fluo-4 of the single wavelength. With a single addition, the assay is easy to perform and desirable in a high thoroughput environment. The assay can be used in a convenient 96-well or 384-well microtiter-plate format and readily adapted to automation.