ABTS

ABTS

Names
IUPAC name 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid)
Identifiers
CAS Number	30931-67-0 N
3D model (Jmol)	Interactive image Interactive image
ChemSpider	4576521 Y
ECHA InfoCard	100.045.800
InChI InChI=1S/C18H18N4O6S4/c1-3-21-13-7-5-11(31(23,24)25)9-15(13)29-17(21)19-20-18-22(4-2)14-8-6-12(32(26,27)28)10-16(14)30-18/h5-10H,3-4H2,1-2H3,(H,23,24,25)(H,26,27,28)/b19-17-,20-18+ Y Key: ZTOJFFHGPLIVKC-YAFCTCPESA-N Y InChI=1/C18H18N4O6S4/c1-3-21-13-7-5-11(31(23,24)25)9-15(13)29-17(21)19-20-18-22(4-2)14-8-6-12(32(26,27)28)10-16(14)30-18/h5-10H,3-4H2,1-2H3,(H,23,24,25)(H,26,27,28)/b19-17-,20-18+ Key: ZTOJFFHGPLIVKC-YAFCTCPEBW
SMILES CCN1/C(Sc2cc(ccc12)S(O)(=O)=O)=N/N=C/3Sc4cc(ccc4N3CC)S(O)(=O)=O O=S(=O)(O)c1ccc2N(C(\Sc2c1)=N\N=C4\Sc3cc(ccc3N4CC)S(=O)(=O)O)CC
Properties
Chemical formula	C18H18N4O6S4
Molar mass	548.7 g/mol
Hazards
R-phrases (outdated)	R36 R37 R38
S-phrases (outdated)	S26-S36
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

In biochemistry, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) or ABTS is chemical compound used to observe the reaction kinetics of specific enzymes. A common use for it is in the enzyme-linked immunosorbent assay (ELISA) to detect for binding of molecules to each other.

It is commonly used as a substrate with hydrogen peroxide for a peroxidase enzyme (such as horseradish peroxidase) or alone with blue multicopper oxidase enzymes (such as laccase or bilirubin oxidase). Its use allows the reaction kinetics of peroxidases themselves to be followed. In this way it also can be used to indirectly follow the reaction kinetics of any hydrogen peroxide-producing enzyme, or to simply quantify the amount of hydrogen peroxide in a sample.

The formal reduction potentials for ABTS are high enough for it to act as an electron donor for the reduction of oxo species such as molecular oxygen and hydrogen peroxide, particularly at the less-extreme pH values encountered in biological catalysis. Under these conditions, the sulfonate groups are fully deprotonated and the mediator exists as a dianion..

This compound is chosen because the enzyme facilitates the reaction with hydrogen peroxide, turning it into a green and soluble end-product. Its new absorbance maximum of 420 nm light (ε = 3.6 × 10⁴ M^–1 cm^–1) can easily be followed with a spectrophotometer, a common laboratory instrument. It is sometimes used as part of a glucose estimating reagent when finding glucose concentrations of solutions such as blood serum.