From Wikipedia, the free encyclopedia
Jump to: navigation, search
Skeletal formula of tetradeprotonated fluo-4
MeSH Fluo-4
Jmol-3D images Image 1
Image 2
Molecular formula C36H30F2N2O13
Molar mass 736.63 g mol−1
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Fluo-4 is used to measure calcium (Ca2+) concentrations inside living cells, and is often used for high-throughput screening of receptor ligands and calcium permeable ion channels.

The green-fluorescent calcium indicator, Fluo-4, is an improved version of the calcium indicator, Fluo-3. It is commonly used as the non-fluorescent acetoxymethyl ester (Fluo-4 AM) which is cleaved inside the cell to give the free, fluorescent Fluo-4. It loads faster, is brighter at equivalent concentrations and is well-excited by the 488 nm line of the argon-ion laser which is often used in biological research laboratories.[1] The sole distributor and owner of the patents is Invitrogen which acquired the original inventor Molecular Probes.


  1. ^ Gee KR, Brown KA, Chen WN, Bishop-Stewart J, Gray D, Johnson I (February 2000). "Chemical and physiological characterization of fluo-4 Ca(2+)-indicator dyes". Cell Calcium 27 (2): 97–106. doi:10.1054/ceca.1999.0095. PMID 10756976.