Fluo-3

Fluo-3

Names
IUPAC name {[2-(2-{2-[Bis(carboxymethyl)amino]-5-(2,7-dichloro-6-hydroxy-3-oxo-3H-xanthen-9-yl)phenoxy}ethoxy)-4-methylphenyl](carboxymethyl)amino}acetic acid
Identifiers
CAS Number	123632-39-3
ChEMBL	ChEMBL509919
ChemSpider	94730
Jmol interactive 3D	Image
PubChem	104978
InChI InChI=1S/C36H30Cl2N2O13/c1-18-2-4-24(39(14-32(43)44)15-33(45)46)30(8-18)51-6-7-52-31-9-19(3-5-25(31)40(16-34(47)48)17-35(49)50)36-20-10-22(37)26(41)12-28(20)53-29-13-27(42)23(38)11-21(29)36/h2-5,8-13,41H,6-7,14-17H2,1H3,(H,43,44)(H,45,46)(H,47,48)(H,49,50) Key: OZLGRUXZXMRXGP-UHFFFAOYSA-N InChI=1/C36H30Cl2N2O13/c1-18-2-4-24(39(14-32(43)44)15-33(45)46)30(8-18)51-6-7-52-31-9-19(3-5-25(31)40(16-34(47)48)17-35(49)50)36-20-10-22(37)26(41)12-28(20)53-29-13-27(42)23(38)11-21(29)36/h2-5,8-13,41H,6-7,14-17H2,1H3,(H,43,44)(H,45,46)(H,47,48)(H,49,50) Key: OZLGRUXZXMRXGP-UHFFFAOYAI
SMILES O=C(O)CN(c5ccc(cc5OCCOc4c(N(CC(=O)O)CC(=O)O)ccc(C=1c3c(OC=2C=1\C=C(\Cl)C(=O)C=2)cc(O)c(Cl)c3)c4)C)CC(=O)O
Properties
Chemical formula	C36H30Cl2N2O13
Molar mass	769.54 g·mol^−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Fluo-3 is a fluorescence indicator of intracellular calcium (Ca²⁺). It is used to measure Ca²⁺ inside living cells in flow cytometry and confocal laser scanning microscopy using visible light excitation (compatible with argon laser sources operating at 488 nm). Fluo-3 is an essentially nonfluorescent compound, but upon binding of Ca²⁺ its fluorescence increases sharply with an emission maximum at 525 nm suitable for conventionally used detectors designed for fluorescein isothiocyanate (FITC) measurements. This large change in fluorescence coupled with a good yield of photons provides very high contrast which allowed the detection of microscopic Ca²⁺ release events inside cells called "Calcium sparks".^[1] Whereas the salts of fluo-3 are unable to penetrate cells, loading can be achieved using its acetoxymethyl (AM) ester derivative. Once inside the cell, unspecific esterases cleave the ester effectively trapping fluo-3.^[2]

As calcium is a key second messenger within cells, the specific properties of fluo-3 enable researchers to investigate the time-resolved dynamics of intracellular signal transduction in a diverse range of cells.^[3][4]

References

1. Cheng, H., Lederer, W.J. & Cannell, M.B., 1993. Calcium Sparks - Elementary Events Underlying Excitation-Contraction Coupling in Heart-Muscle. Science, 262(5134), pp.740–744. Available at: http://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&id=8235594&retmode=ref&cmd=prlinks.
2. Haugland, RP. Handbook of Fluorescent Probes and Research Products. Molecular Probes, 2010
3. Gamsjäger, T. Flow Cytometry of Intracellular Calcium in Platelets. Grin, 2012
4. Lambert, DG. Calcium Signaling Protocols. Humana Press, 2006