Fluo-4, AM Ester

Membrane-permeant AM ester form of Fluo-4 that can enter into into cells via incubation. Fluo-4 AM ester itself does not bind Ca², but it is readily hydrolyzed to Fluo-4 by endogenous esterases once the dye is inside the cells. Fluo-4 AM ester is often used to measure intracellular calcium in high throughput drug screening. </p> Fluo-4 is an analog of Fluo-3 with the two chlorine substituents replaced by fluorines, which results in increased fluorescence excitation at 488 nm that gives higher fluorescence signal. Fluo-4 has its absorption maximum at 494 nm, thus making it excitable by the argon-ion laser. Fluo-4 is essentially nonfluorescent without Ca² present, but the fluorescence increases at least 100 times on Ca² binding. Also, because Fluo-4 binds Ca² more weakly (higher Kd) than do fura-2 and indo-1, it is more useful for measuring high transient Ca² concentration during Ca² spikes. </p> Fluo-4 AM ester can be used to detect intracellular free calcium by fluorescence microscopy, flow cytometry, or fluorescence microplate reader. </p> We also sell Fluo-4 as a membrane-impermeant pentapotassium salt version. </p> <ul> </p> <li>Orange red solid soluble in DMSO</li> </p> <li>Store -20°C and protect from light, especially when in solution</li> </p> <li>Ex/Em of Ca²€“bound form: 494/506 nm</li> </p> <li>K_d for Ca² in buffer: ~335 nM</li> </p> <li>C₅₁H₅₀F₂N₂O₂₃</li> </p> <li>MW: 1096.95</li> </p> <li>[273221-67-3]</li> </p> </ul>