Parameters 

Appearance: Orange-red powder soluble in DMSO (F3013) 

Ex/Em of Ca²⁺ –bound form: 494/516 nm 

CAS No.: 273221-67-3 

Molecular Formula: C₅₁H₅₀F₂N₂O₂₃ 

Molecular Weight: 1096.94

Storage 

Store at -20°C and protect from light. When stored as directed, product is stable for at least 12 months.

Description 

Fluo-4, AM ester 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 inside cells.

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, Fluo-4 was twice as strong as fluo-3 in fluorescence intensity. Fluo-4 AM ester can be used to detect intracellular free calcium by fluorescence microscopy, flow cytometry.

Notes 

1. If a serum-containing medium is used, the esterase in the serum will decompose the AM , thereby reducing the effect of Fluo-4, AM entering the cells. In addition, the medium containing phenol red will slightly increase the background value, so you should try to remove the residue of the medium before adding the working solution. 

2. There are quenching problems with fluorescent dyes. Please avoid light to slow down the fluorescence quenching. 

3. This Fluo-4, AM is easy to absorb moisture. After removing it from the refrigerator, please make sure to open it in a dry environment at room temperature. As the reagent is extremely small, centrifuge it briefly before opening to ensure that the powder falls to the bottom of the tube. 

4. Fluo-4, AM decomposes easily in contact with water. If it cannot be used up at one time, it is recommended to store the solution in small quantities.