Fluo-4, AM Ester Fluorescent Calcium Indicator
Our Fluo-4, AM Ester is a non-ratiometric calcium indicator that increases in fluorescence intensity upon calcium binding. Calcium imaging is widely used to measure neuronal activity.
SKU: 81-3006
Ships: 1-5 business days
Product Details
To study the roles of calcium, a key intracellular messenger in cells, it is essential to quantitatively monitor its concentration. The most widely used method of Ca2+ detection is the use of fluorescent Ca2+ indicators. 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 is a membrane-permeant form of Fluo-4 calcium indicator that can enter into into cells via incubation.
EM, ICC, IHC
1096.95 Da
Kd: 335 nM, Ex: 494 nm, Em: 516 nm
Store at –20°C, with desiccant; protect from light.
Solid
Membrane-permeant, non-ratiometric; can be loaded into cells via incubation.
For research use only. Not intended for therapeutic or diagnostic use. Use of all products is subject to our terms and conditions, which can be viewed on our website.
United States
Stable for 12 months after date of receipt.
Shipped at ambient temperature with desiccant; protected from light

