Indo-1

Indo-1
Names
	IUPAC name 2-[4-(bis(carboxymethyl)amino)-3-[2-[2-(bis(carboxymethyl)amino)- 5-methylphenoxy]ethoxy]phenyl]-1H-indole-6-carboxylic acid
	Other names Indo-1
Identifiers
CAS Number	96314-96-4 ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:52084 ;
ChemSpider	94791 ;
PubChem CID	105060;
UNII	N18RMK75W1 ;
CompTox Dashboard (EPA)	DTXSID60242202 ;
	InChI InChI=1S/C32H31N3O12/c1-18-2-6-24(34(14-28(36)37)15-29(38)39)26(10-18)46-8-9-47-27-13-20(5-7-25(27)35(16-30(40)41)17-31(42)43)22-11-19-3-4-21(32(44)45)12-23(19)33-22/h2-7,10-13,33H,8-9,14-17H2,1H3,(H,36,37)(H,38,39)(H,40,41)(H,42,43)(H,44,45) Key: AMHAQOBUZCQMHN-UHFFFAOYSA-N ; InChI=1/C32H31N3O12/c1-18-2-6-24(34(14-28(36)37)15-29(38)39)26(10-18)46-8-9-47-27-13-20(5-7-25(27)35(16-30(40)41)17-31(42)43)22-11-19-3-4-21(32(44)45)12-23(19)33-22/h2-7,10-13,33H,8-9,14-17H2,1H3,(H,36,37)(H,38,39)(H,40,41)(H,42,43)(H,44,45) Key: AMHAQOBUZCQMHN-UHFFFAOYAU;
	SMILES O=C(O)CN(c4ccc(cc4OCCOc3c(N(CC(=O)O)CC(=O)O)ccc(c2cc1ccc(cc1[nH]2)C(=O)O)c3)C)CC(=O)O;
Properties
Chemical formula	C32H31N3O12
Molar mass	649.60 g/mol
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Indo-1 is a popular dye that is used as a ratiometric calcium indicator similar to Fura-2. In contrast to Fura-2, Indo-1 has a dual emissions peak and a single excitation. The main emission peak in calcium-free solution is 475 nm while in the presence of calcium the emission is shifted to 400 nm. It is widely used in flow cytometry and laser scanning microscopy, due to its single excitation property. However, its use for confocal microscopy is limited due to its photo-instability caused by photobleaching. Indo-1 is also able to keep possession of its ratiometric emission, dissimilar to Fura-2.^[1] The penta potassium salt is commercially available and preferred to the free acid because of its higher solubility in water. While Indo-1 is not cell permeable the penta acetoxymethyl ester Indo-1 AM enters the cell where it is cleaved by intracellular esterases to Indo-1. The synthesis and properties of Indo-1 were presented in 1985 by the group of Roger Y Tsien.^[2]

In intact heart muscle, Indo-1, in combination with bioluminescent protein aequorin, can be utilized as a tool to distinguish between the internal and exterior inotropic regulation processes.^[3]

References

^ Paredes, R. Madelaine; Etzler, Julie C.; Watts, Lora Talley; Zheng, Wei; Lechleiter, James D. (November 2008). "Chemical calcium indicators". Methods. 46 (3): 143–151. doi:10.1016/j.ymeth.2008.09.025. PMC 2666335.
^ Grynkiewicz G, Poenie M, Tsien RY (1985). "A new generation of Ca2+ indicators with greatly improved fluorescence properties". J. Biol. Chem. 260 (6): 3440–50. doi:10.1016/S0021-9258(19)83641-4. PMID 3838314.
^ Endoh, Masao (2006). "Signal Transduction and Ca2+ Signaling in Intact Myocardium". Journal of Pharmacological Sciences. 100 (5): 525–537. doi:10.1254/jphs.CPJ06009X. ISSN 1347-8613.

[1] Paredes, R. Madelaine; Etzler, Julie C.; Watts, Lora Talley; Zheng, Wei; Lechleiter, James D. (November 2008). "Chemical calcium indicators". Methods. 46 (3): 143–151. doi:10.1016/j.ymeth.2008.09.025. PMC 2666335.

[pmid3838314-2] Grynkiewicz G, Poenie M, Tsien RY (1985). "A new generation of Ca2+ indicators with greatly improved fluorescence properties". J. Biol. Chem. 260 (6): 3440–50. doi:10.1016/S0021-9258(19)83641-4. PMID 3838314.

[3] Endoh, Masao (2006). "Signal Transduction and Ca2+ Signaling in Intact Myocardium". Journal of Pharmacological Sciences. 100 (5): 525–537. doi:10.1254/jphs.CPJ06009X. ISSN 1347-8613.

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