Fura-2
Fura-2, an aminopolycarboxylic acid, is a ratiometric fluorescent dye which binds to free intracellular calcium.[1] It was the first widely used dye for calcium imaging, and remains very popular. Fura-2 is excited at 340 nm and 380 nm of light, and the ratio of the emissions at those wavelengths is directly related to the amount of intracellular calcium. Regardless of the presence of calcium, Fura-2 emits at 510 nm of light. The use of the ratio automatically cancels out confounding variables, such as variable dye concentration and cell thickness, making Fura-2 one of the most appreciated tools to quantify calcium levels. The high photon yield of fura-2 allowed the first real time (video rate) measurements of calcium inside living cells in 1986.[2] More recently, genetically encoded calcium indicators based on spectral variants of the green fluorescent protein, such as Cameleons,[3] have supplemented the use of Fura-2 and other small molecule dyes for calcium imaging, but Fura-2 remains faster.
Identifiers | |
---|---|
3D model (JSmol) |
|
ChemSpider | |
PubChem CID |
|
UNII | |
CompTox Dashboard (EPA) |
|
| |
| |
Properties | |
C29H22N3O14K5 | |
Molar mass | 831.99 g/mol |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references |
References
- Grynkiewicz, G.; Poenie, M. & Tsien, R.Y. (1985). "A new generation of Ca2+ indicators with greatly improved fluorescence properties*" (PDF). J. Biol. Chem. 260 (6): 3440–3450. doi:10.1016/S0021-9258(19)83641-4. PMID 3838314.
- Cannell, MB; Berlin, JR; Lederer, WJ (1987). "Intracellular calcium in cardiac myocytes: calcium transients measured using fluorescence imaging". Society of General Physiologists Series. 42: 201–14. PMID 3505361.
- Tsien, Roger Y.; Miyawaki, Atsushi; Llopis, Juan; Heim, Roger; McCaffery, J. Michael; Adams, Joseph A.; Ikura, Mitsuhiko (1997). "Fluorescent indicators for Ca2+based on green fluorescent proteins and calmodulin". Nature. 388 (6645): 882–7. Bibcode:1997Natur.388..882M. doi:10.1038/42264. PMID 9278050. S2CID 13745050.