Fluo-4, AM ester, 50UG

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. 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. Fluo-4 AM ester can be used to detect intracellular free calcium by fluorescence microscopy, flow cytometry, or fluorescence microplate reader. We also sell Fluo-4 as a membrane-impermeant pentapotassium salt version.

• Orange red solid soluble in DMSO
• Store -20C and protect from light, especially when in solution
• Ex/Em of Ca² €"bound form: 494/506 nm
• K_d for Ca² in buffer: ca.335 nM
• C₅₁H₅₀F₂N₂O₂₃
• MW: 1096.95
• [273221-67-3]

F)-35C to -5C