How does ABTS assay work?

The ABTS assay measures the relative ability of antioxidants to scavenge the ABTS generated in aqueous phase, as compared with a Trolox (water soluble vitamin E analogue) standard. The ABTS is generated by reacting with a strong oxidizing agent (eg, potassium permanganate or potassium persulfate) with the ABTS salt.

What is the difference between ABTS and DPPH?

Differences between DPPH and ABTS radical scavenging activities can be ascribed to reaction media. DPPH assay is conventionally conducted under 50% ethanol /water, whilst ABTS assay is carry out in aqueous conditions. The electronic transfer was faster than A samples during the reaction.

What kind of compounds can be identified with the ABTS test?

Based on the special chemical properties of formed free radicals, ABTS assay has been used to determine the antioxidant capacity of food products. For example, polyphenol compounds, which widely exist in fruit, can quench free radicals inside human body, thus prevent oxidative damage by free radicals.

Is ABTS a free radical?

Two free radicals that are commonly used to assess antioxidant activity in vitro are 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH). However, both of these radicals are foreign to biological systems.

What is ABTS ELISA?

ABTS Substrate is a water-soluble peroxidase substrate that yields a measurable green end product for use in ELISA methods. ABTS (2,2′-Azinobis [3-ethylbenzothiazoline-6-sulfonic acid]-diammonium salt) is a water-soluble HRP substrate that yields a green end product upon reaction with peroxidase.

What ABTS means?

American Board of Thoracic Surgery. ABTS.

What is ABTS radical scavenging assay?

The ABTS•+ and DPPH assays are widely used methods for the assessment of the antioxidant capacities of natural products, they both are spectrophotometric techniques based on quenching of stable colored radicals (ABTS•+ or DPPH) and show the radical scavenging ability of antioxidants even when present in complex …

What is the difference between DPPH and FRAP?

The DPPH method has the ability of the various antioxidants to donate an electron or hydrogen radical to the stable DPPH free radical. And FRAP method compares antioxidants based on their ability to reduce ferric (Fe3+) to ferrous (Fe2+) ion through the donation of an electron, with the resulting ferrous ion (Fe2+).

How do you prepare ABTS stock solution?

The ABTS solution was prepared by mixing an equal volume of a 7 mmol/L ABTS stock solution with a 2.45 mmol/L potassium persulfate solution. The mixture was then stored in the dark at room temperature for 12–16 h.

How do you calculate ABTS?

Percent inhibition of absorbance at 734 nm was calculated using the formula, ABTS·+ scavenging effect (%) = ((AB–AA)/ AB)×100 (2), where, AB is absorbance of ABTS radical + methanol; AA is absorbance of ABTS radical + sample extract/standard. Trolox was used as standard substance.

What is the principle of DPPH assay?

The assay is based on the measurement of the scavenging capacity of antioxidants towards it. The odd electron of nitrogen atom in DPPH is reduced by receiving a hydrogen atom from antioxidants to the corresponding hydrazine (Contreras-Guzman and Srong 1982).

What is the ABTS radical cation reaction?

The ABTS radical cation is reactive towards most antioxidants including phenolics, thiols and Vitamin C. During this reaction, the blue ABTS radical cation is converted back to its colorless neutral form. The reaction may be monitored spectrophotometrically. This assay is often referred to as the Trolox equivalent antioxidant capacity (TEAC) assay.

What does Abts mean in chemistry?

The 2,2′-azinobis- (3-ethylenebenzothiazoline)-6-sulfonic acid (ABTS) assay is another commonly applied antioxidant assay. When an antioxidant is added, the ABTS loses its blue-green color and it is reduced to ABTS [139].

How are the results of the ABTS assay reported?

The results of the ABTS assay are typically reported in a dose-dependent manner (moles ABTS radical cation consumed/moles antioxidant per a given time interval) ( Pellegrini et al., 1999 ).

What happens when antioxidant is added to ABTS?

When an antioxidant is added, the ABTS loses its blue-green color and it is reduced to ABTS [139]. It is a simple and speedy method; however, since it is a synthetic radical, unspecific reactions can occur [140].