Fura-2, Pentaammonium Salt

Fura-2, pentaammonium salt is a ratiometric fluorescent dye that binds to free intracellular calcium. It is membrane-impermeant and may be loaded into cells via microinjection or scrape loading. A major use of Fura-2 is in drug discovery, for measuring intracellular calcium mobilization after activation of G protein-coupled receptors (GPCRs) and calcium channels. Upon calcium binding, the fluorescent excitation maximum of the indicator undergoes a blue shift from 363 nm (Ca2-free) to 335 nm (Ca2-saturated), while the fluorescence emission maximum is relatively unchanged at ~510 nm.Light yellow solid soluble in DMSO,Store at 4°C and protect from light, especially in solution,Kd: 145 nM (22°C in pH 7.2 buffer),&lamba, Ex/&lamba,Em (no Ca2) = 363/512 nm, &lamba, Ex/&lamba, Em (high Ca2) = 335/505 nm,epsilon (363 nm, no Ca2) = 27,000 M-1cm-1, epsilon (335 nm, high Ca2) = 35,000 M-1cm-1,C29H37N8O14,MW: 721,