What is the principle of FRAP assay?
FRAP assay. Ferric reducing ability of plasma (FRAP) assay is based on the principle of reduction of ferric-tripyridyltriazine (Fe3+-TPTZ) complex to ferrous tripyridyltriazine (Fe2+-TPTZ) by the antioxidants of a sample at low pH [12].
How do you make a FRAP assay?
The FRAP reagent was prepared by mixing 25 ml of 300.0 mmol/L acetate buffer, 2.5 ml of 10 mmol/L TPTZ solution, and 2.5 ml of 20 mmol/L FeCl3 solution in a 10:1:1 ratio. 10 μL of sample was mixed with 200 μL of FRAP reagent; the contents were mixed vigorously.
What is reducing power assay?
Reducing power assay method is based on the principle that substances, which have reduction potential, react with potassium ferricyanide (Fe3+) to form potassium ferrocyanide (Fe2+), which then reacts with ferric chloride to form ferric–ferrous complex that has an absorption maximum at 700 nm.
How do you make 10mm TPTZ?
To make a 10 mM 2,4,6-tri(2-pyridyl)-1,3,5-triazine (TPTZ) solution, add 0.31 g to 100 mL HCl (40 mM). This solution is stable for at least 1 month at 4°C.
What are antioxidant assays?
Assays developed to evaluate the antioxidant activity of plants and food constituents vary. Therefore, to investigate the antioxidant activity of chemical(s), choosing an adequate assay based on the chemical(s) of interest is critical. There are two general types of assays widely used for different antioxidant studies.
What is ferric reducing antioxidant power?
Ferric reducing ability of plasma (FRAP, also Ferric ion reducing antioxidant power) is an antioxidant capacity assay that uses Trolox as a standard. This assay is often used to measure the antioxidant capacity of foods, beverages and nutritional supplements containing polyphenols.
What is FRAP test?
FRAP assay stands for Ferric Reducing Antioxidant Power Assay. The assay measures the antioxidant potential in samples through the reduction of ferric iron (Fe3+) to ferrous iron (Fe2+) by antioxidants present in the samples.
What is FRAP value?
The FRAP value measures the reduction of the ferric ion (Fe3+) to the ferrous ion (Fe2+) by donor electrons in the sample [31].
What is ABTS assay?
In biochemistry, ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) is a 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 the binding of molecules to each other.
Why antioxidant assay is important?
For most of the plant products, the compounds responsible for the antioxidant effects are phenolic. Thus a preliminary assessment would begin with the total phenol assay. The antioxidants generally scavenge these radicals thus it is important to measure the free radical scavenging activity using DPPH.
How does FRAP analysis work?
In FRAP, a specific area of a cell or tissue is photobleached by intense laser light, removing fluorescence from this area. This area is typically a cell membrane or area where diffusion occurs, such as the nucleus, as FRAP requires fluorescent molecules to move around freely in order to function.
What is the ferric reducing antioxidant power assay?
The ferric reducing antioxidant power (FRAP) assay is a typical ET-based method that measures the reduction of ferric ion (Fe 3+ )-ligand complex to the intensely blue-colored ferrous (Fe 2+) complex by antioxidants in an acidic medium.
What is ferric reducing antioxidant power (FRAP)?
The ferric reducing antioxidant power (FRAP) mechanism is based on electron transfer rather than hydrogen atom transfer ( Prior et al., 2005 ). The FRAP assay is based on the ability of PH to reduce Fe 3+ to Fe 2+.
What is the ferric reducing ability of plasma?
The ferric reducing ability of plasma is a simple, rapid, and useful assay to measure antioxidant potential in vivo. The principle is similar to the in vitro FRAP assay.
What is the best ferric reagent for FRAP assays?
More recently, potassium ferricyanide has been the most popular ferric reagent used in FRAP assays. In the latter case, Prussian blue is produced as the end product, which is quantified spectrophotometrically and indicates the reducing power of the antioxidants tested.
