frap assay using potassium ferricyanide


Drabkins reagent is used in measuring haemoglobin from blood samples. The crude methanol and its fractionated extracts (hexane and ethyl acetate) were dissolved in methanol whilst the water extracts were dissolved in distilled water. add 3 mL of 5X Assay Buffer to 12 mL of deionized water). It is soluble in water and its solution shows some green-yellow fluorescence. Explain the main limitations of the assay. The Fe2+ forms a colored complex at OD 590 nm proportional to the FRAP in the sample. Warm to room temperature before use. Part A Experiment. Figure 1. (2008). Sodium dodecyl sulfate solution (1%, w / v ) was prepared by dissolving 1.0 g of SDS in water and diluting to 100 mL with water (Berker et al. 5.3 FeCl3 Solution Ready to use as supplied. FRAP assay. According to this method, the aliquots of various concentrations of the standard and test sample extracts (10 to 100 g/ml) in 1.0 ml of deionized water were mixed with 2.5 ml of (pH 6.6) phosphate buffer and 2.5 ml of (1%) potassium ferricyanide. Briefly, Reagents for FRAP assay a) Acetate buffer 300 mM pH 3.6: b) TPTZ (2, 4, 6-tripyridyl-s- triazine): (M.W. This experiment involves constructing a standard curve with concentrations of 0-1.0mM ferrous sulphate (FeSO4, Fe2+) and carrying out the FRAP assay on 6 food samples and 4 plasma samples. Prussian blue Biochem. The Power Assay (FRAP) The reducing power of MEMCP was determined using the method reported by Oyaizu [16] but with slight (0.2 M, pH 6.6) and 2.5 mL of 1% potassium ferricyanide [K 3 Fe(CN) 6] solution. By Asgar Ali. Mix thoroughly until homogeneous. Methods. Iron(III)-based TAC assays, especially the most widely used FRAP (ferric-reducing antioxidant power), play an important role in this regard. to chelate metal ions by FRAP assay. lows: 300 ml freshly prepared FRAP reagent was The FRAP assay is described, and results are pre- Use within two months. The mixture was incubated at 50C in water bath for 20 min after cooling. For antioxidant capacity assays, the ferric reducing antioxidant power assay (FRAP) , 2,2-diphenyl-1-picrylhydrazyl (DPPH) method , and potassium ferricyanide reducing antioxidant power (PFRAP) technique was used as described previously . An overview of Potassium Dihydrogen : second harmonic generation, 6 mm 5, important nonlinear optical, inertial confinement fusion, Mm Potassium Dihydrogen, Deuterated Potassium Dihydrogen, L Potassium Dihydrogen, M Potassium Dihydrogen - Sentence Examples Optimizing parameters on the antioxidant capacity of watermelon pulp using conventional orbital shaker and ultrasound-assisted extraction methods. K043-H1 - $ 470.00. The total polyphenol content 25 REDUCING POWER ASSAY(9) 1 ml extract+ 2.5 ml phosphate buffer(6.6) +2.5 ml of potassium ferricyanide 50C 20 min incb Add 2.5 ml of trichloroacetic acid 10 mins 3000rpm Upper layer+2.5 ml of distiiled water+0.5 ml of FeCl3 Absorbance 700 nm Mix thoroughly until homogeneous. FRAP (Ferric Reducing Antioxidant Power) assay The reaction detects compounds with redox potentials of <0.7 V (the redox potential of Fe3+-TPTZ), so FRAP is a reasonable screen for the ability to maintain redox status in cells or tissues. The ferric reducing capacity of extracts was investigated by using the potassium ferricyanide-ferric chloride method . Explain the main limitations of the assay. However, many problems have been reported in the application of the FRAP assay, the most serious one being the incomplete oxidation of a number of antioxidants during the time protocol of the assay. 5.4 Ferrous Standard (2 mM) Ready to use as supplied. Reducing power assay This assay was carried out using a protocol16 with little modifications. ii. In vivo anti-inflammatory activity was evaluated by the paw edema assay induced by Carrageenin in rat model. The ferric reducing capacity of extracts was investigated by using the potassium ferricyanide-ferric chloride method . 5.1 FRAP Assay Buffer Ready to use as supplied. In this assay the ability of butanol and hexane leaf extract of P. aculeata to reduce ferric ions was determined. Accuracy of the potentiometric titration of cobalt with ferricyanide in ammoniacal medium. A Cobas Fara centrifugal limiting factor of FeII-TPTZ, and hence color, formation analyzer was used to perform the FRAP assay as fol-is the reducing ability of the sample. By Nor Azizah Mohammad. 6. potassium ferricyanide, trichloroacetic acid, disodium hydrogenphosphate, Rutin, Mueller-Hinton agar Antioxidant capacity of extracts was determined using FRAP assay (Figure 3). Biochem. Article. The mixture was incubated at 50C for 20 min. Use within two months. lows: 300 ml freshly prepared FRAP reagent was The FRAP assay is described, and results are pre- Download PDF. These are 1,10-phenanthroline, 4,7-diphenyl-1,10-phenanthroline (batho-phenanthroline), 2,4,6-tris(2-pyridyl)-1,3,5-triazine(TPTZ), 8,27 and ferricyanide. The cyanmethemoglobin levels is estimated at 530nm. Results are expressed in mM TE/g fresh mass. Basically, ET-based assays include ABTS assay, DPPH assay, ferrous oxidation-xylenol orange (FOX) assay, ferric thiocyanate (FTC) assay, ferric reducing/antioxidant power (FRAP) assay, potassium ferricyanide reducing power (PFRAP) assay, and cupric reducing antioxidant power (CUPRAC) assay (Brand-Williams, Cuvelier, & Berset, 1995). . determined by 1,1diphenyl2picrylhydrazyl radical assay as 67.4 12.5 g/ml and following FRAP assay as 127.8 12.4 g/ml Major bioactive metabolites identified by gas chromatographymass spectrometry analysis included arachidonic acid inhibitor, namely After incubation, 2.5 mL Use within two months. mixed with 2.5 mL of phosphate buffer solution (0.2 M, pH 6.6) and 2.5 mL of 1% The yield of essential oil was determined using the formula below: potassium ferricyanide and The maximum reducing ability in the FRAP assay was observed in aqueous flower extracts of S. venulosa (195.770.14 M Fe (II) /g to 500 L by using 2.0 M phosphate buffer and 1% potassium ferricyanide, then the tubes were kept for incubation at 50C for 20 min. 3.6. Keep on ice while in use. Phosphatebuffer preparation 2010b ). 312.34), 10 mM in 40 mM HCl (M.W. 5.1 FRAP Assay Buffer Ready to use as supplied. Ferric Reducing Antioxidant Power (FRAP) Assay Ferric reducing antioxidant power of extract was determined using the method previously described (Lee et al., 2018). Can you use this assay with serum or plasma samples? 6. [Google Scholar] Berker, K.I. Reductive ability of the extract was also tested by the complex formation with potassium ferricyanide. BioAssay Systems' FRAP Assay Kit (DFRAP-250) measures antioxidant potential to reduce Fe3+ to Fe2+. ii. A Cobas Fara centrifugal limiting factor of FeII-TPTZ, and hence color, formation analyzer was used to perform the FRAP assay as fol-is the reducing ability of the sample. The standard curve was linear between 25 and 800 mM Trolox. 30164-Article Text-56583-2-10-20191101 - Read online for free. This chapter presents concepts, technical tips and calculations, along with some illustrative examples of how the ferric reducing/antioxidant power (FRAP) assay has been applied in the health and life sciences fields. 1. Optimizing parameters on the antioxidant capacity of watermelon pulp using conventional orbital shaker and ultrasound-assisted extraction methods. capacity of the leaves extracts using the FRAP Assay. The mixture was incubated at 50C in water bath for 20 min after cooling. The antioxidant potential of AS and wound healing activity were addressed using skin. This experiment involves constructing a standard curve with concentrations of 0-1.0mM ferrous sulphate (FeSO4, Fe2+) and carrying out the FRAP assay on 6 food samples and 4 plasma samples. Similarly, the potassium ferricyanide reduction (FRAP) and ABTS+ of methanol extract. Reaction mixture was incubated at 50 for 20 min. Antioxidants help neutralize or destroy Reactive Oxygen Species (ROS) or free radicals before they can damage cells. Briefly, 1.0 mL of extract was mixed with 2.5 mL of phosphate buffer (0.2 M, pH 6.6) and 2.5 mL potassium ferricyanide (1%). In vivo anti-inflammatory activity was evaluated by the paw edema assay induced by Carrageenin in rat model. potential by potassium ferricyanide and ABTS reduction assay. 3 ml of reaction mixture, containing 250 l of extracts in 2.5 ml 0.2 M phosphate buffer (pH 6.6) was incubated with 2.5 ml potassium ferricyanide (1% w/v) at 50 C for 20 minutes. Share sensitive information only on official, secure websites. The sample/reagent ratio Potassium ferricyanide (1 %, w/v) Potassium ferricyanide 1 % was prepared by dissolving 0.1 g of Potassium ferricyanide Can you use this assay with serum or plasma samples? Ferric Reducing Antioxidant Power (FRAP) Assay Ferric reducing antioxidant power of extract was determined using the method previously described (Lee et al., 2018). It is between FRAP ferric ion reducing antioxidant important to mention that the TAA values of the power and ABTS radical cation scavenging activity same apple obtained by the ABTS assay were suggesting that overall antioxidant activity consistently higher that those obtained by the evaluation results for 15 apple samples using four DPPH assay. The standard curve was linear between 25 and 800 mM Trolox. Using the 2,2,1-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and potassium ferricyanide ferric chloride assay, Marn et al. The FRAP assay is high-throughput, adaptable and can detect antioxidant capacities as low as 0.2 mM Fe 2+ equivalents. It comprises potassium ferricyanide, potassium cyanide and potassium dihydrogen phosphate as components. In the FRAP assay, excess FeIII is used, and the rate-Automated FRAP assay. More recently, potassium ferricyanide has been the most common ferric reagent used in FRAP tests. The assay described here measures the ferric reducing ability of plasma (FRAP). This chapter presents concepts, technical tips and calculations, along with some illustrative examples of how the ferric reducing/antioxidant power (FRAP) assay has been applied in the health and life sciences fields. However, many problems have been reported in the application of the FRAP assay, the most serious one being the incomplete oxidation of a number of antioxidants during the time protocol of the assay. According to this method, the aliquots of various concentrations of the standard and test sample extracts (10 to 100 g/ml) in 1.0 ml of deionized water were mixed with 2.5 ml of (pH 6.6) phosphate buffer and 2.5 ml of (1%) potassium ferricyanide. standard ascorbic acid. This paper focuses on types of damaging free radicals generated in metabolic processes and also gives an insight of mechanistic aspect of various in-vitro methods for evaluation of [] To all the tubes, 2.5 ml of 0.2 M phosphate buffer (pH-6.6) and 2.5 ml of 1% Potassium ferricyanide was added and incubated at 50C for 20 min. Ferric reducing ability of plasma (FRAP, also Ferric ion reducing antioxidant power) is an antioxidant capacity assay that uses Trolox as a standard. FRAP (Ferric Reducing Antioxidant Power) assay The reaction detects compounds with redox potentials of <0.7 V (the redox potential of Fe3+-TPTZ), so FRAP is a reasonable screen for the ability to maintain redox status in cells or tissues. To all the tubes, 2.5 ml of 0.2 M phosphate buffer (pH-6.6) and 2.5 ml of 1% Potassium ferricyanide was added and incubated at 50C for 20 min. 312.34), 10 mM in 40 mM HCl (M.W. We mixed 200 L of the extract with known concentration with 500 L of phosphate buffer (0.2 M, pH 6.6) and 500 L of 1% potassium ferricyanide K 3 [Fe(CN) 6]. The samples were methanolic extract, different fractions (n-hexane, chloroform) and standard ascorbic acid. The ferric reducing capacity of extracts was investigated by using the potassium ferricyanide-ferric chloride method . Use within two months. The Fe2+ forms a colored complex at OD 590 nm proportional to the FRAP in the sample. R: H = antioxidant radical scavenger; R = antioxidant radical. Potassium ferricyanide oxidizes haemoglobin to methemoglobin and then to cyanmethemoglobin. The solutions prepared were buffer solution (pH 6.6), 1% potassium ferricyanide solution, 10% trichloroacetic acid and 0.1% ferric chloride. 6. Reaction Reagent: Prepare the Reaction Reagent just before use and prepare only enough for immediate applications. Methods: HFECP was assayed on different in vitro free radical models like DPPH, FRAP, ABTS and total antioxidant assay models. The PFRAP (Potassium ferricyanide reducing power) method An absorbance increase can be correlated to the reducing ability of antioxidants/antioxidant extracts. The compounds with antioxidant capacity react with potassium ferricyanide, to form potassium ferrocyanide. By Nor Azizah Mohammad. the accuracy of The DetectX FRAP (Ferric Reducing Antioxidant Power) Detection Kit quantitatively measures antioxidant status in a variety of samples. INTRODUCTION The total antioxidant activity can be measured by the ferric reducing antioxidant power assay (FRAP). Reducing power assay This assay was carried out using a protocol16 with little modifications. The reaction was terminated by adding 2.5 Store at 4C when not in use. In this latter case, Prussian blue is obtained as a final product that may be quantified spectrophotometrically and shows the reducing power of the antioxidants tested. Antioxidants have become a vital part of our lives today. Download PDF. Anal. The mixture was incubated at 50C for 20 min. The potassium ferricyanide assay is another type of FRAP method based on the reduction of Fe (III) to Fe (II), usually abbreviated as PFRAP. It was discovered in 1822 by Leopold Gmelin. The ferric reducing anti-oxidant power (FRAP) assay involved the following steps: a) preparation of samples, b) reactions and c) finally measuring absorbance of sample and standard at 700 nm using spectrophotometer. Basically, ET-based assays include ABTS assay, DPPH assay, ferrous oxidation-xylenol orange (FOX) assay, ferric thiocyanate (FTC) assay, ferric reducing/antioxidant power (FRAP) assay, potassium ferricyanide reducing power (PFRAP) assay, and cupric reducing antioxidant power (CUPRAC) assay (Brand-Williams, Cuvelier, & Berset, 1995). The solutions prepared were buffer solution (pH 6.6), 1% potassium ferricyanide solution, 10% trichloroacetic acid and 0.1% ferric chloride. K043-H1 - $ 470.00. Similarly, the potassium ferricyanide reduction (FRAP) and ABTS+ of methanol extract. Firstly, Diphylleia grayi extract was mixed with 0.2 M sodium phosphate buffer (pH 6.6) and 1% In this assay, ferric ions are reduced to ferrous ions in the presence of an antioxidant (or, a reducing agent) which form a Genetic diversity for agromorphological traits, phytochemical profile, and antioxidant activity in Moroccan sorghum ecotypes. Materials and Methods Extraction and Purification of Compounds from Sargassam wightii The extraction of various compounds from FRAP assay is based on the ability of the compound to produce colour when the colourless Fe3+-TPTZ complex become blue in colour when TPTZ forms (e.g. Phosphatebuffer preparation The maximum reducing ability in the FRAP assay was observed in aqueous flower extracts of S. venulosa (195.770.14 M Fe (II) /g to 500 L by using 2.0 M phosphate buffer and 1% potassium ferricyanide, then the tubes were kept for incubation at 50C for 20 min. Quantity: 1 Quantity: 2 Quantity: 3 Quantity: 4 Quantity: 5 Quantity: 10 Quantity: 15 Quantity: 20 Quantity: 25. 36.46). In our study, Allium subhirsutum L. (AS) was investigated to assess its phenolic profile and bioactive molecules including flavonoids and organosulfur compounds. Following the reduction of the ferric iron, a blue color develops that is read colorimetrically at Anal. Potassium ferricyanide (1 %, w/v) Potassium ferricyanide 1 % was prepared by dissolving 0.1 g of Potassium ferricyanide K4Fe (CN)6, with zinc chloride in the presence of potassium chloride, using uranyl nitrate as an outside indicator. Potassium ferricyanide (1%, w / v) and ferric chloride (0.2%, w / v) solutions were prepared as described in Original Ferricyanide Assay of Reducing Power section. 1996, 239, 7076. 2.6.3. Materials and Methods The leaves of Epipremnum aureum were collected from the campus of Haffkine Institute for Training, Research and phosphate buffer and then 2.5 mL of potassium ferricyanide solution was added. The strongest scavenging activity was observed in methanolic fraction scavenged radicals effectively with IC values of 0.14 0.02 mg/ml. standard ascorbic acid. With authentically pure metallic cobalt and purified potassium ferricyanide. For each reaction, 1 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. Antioxidant activities were evaluated by four assays: an antioxidant activity assay using Saccharomyces cerevisiae, a DPPH ((2, 2-diphenyl-1-picrylhydrazyl) assay to assess free radical scavenging, an assay assessing ferrous ions or iron (II) chelating ability, and a ferric reducing antioxidant power (FRAP) assay.Total phenolic and flavonoid contents were determined using the The FRAP of different extracts of P. hysterophorus was tested using the potassium ferricyanide-ferric chloride method with some modification [24, 25]. FRAP assay. The present study was focused to analyze the antibacterial and antioxidant activities of a widely used traditional medicinal plant, Blumea lanceolaria. 10 mg of each crude and partition extract was individually dissolved in 1 mL of corresponding extracting solvent to produce the stock of sample solution at 10,000 ppm. 3 ml of reaction mixture, containing 250 l of extracts in 2.5 ml 0.2 M phosphate buffer (pH 6.6) was incubated with 2.5 ml potassium ferricyanide (1% w/v) at 50 C for 20 minutes. 36.46). Accuracy of the potentiometric titration of cobalt with ferricyanide in ammoniacal medium. The existing ferricyanide/Prussian blue assay of reducing capacity measurement was optimized so as to obtain a more reproducible, linear and additive response from antioxidants. A locked padlock) or https:// means youve safely connected to the .gov website. This bright red salt contains the octahedrally coordinated [Fe (CN) 6] 3 ion. Medicinal plants are being used for the treatment of several ailments by the local tribes in Mizoram, North East India. add 3 mL of 5X Assay Buffer to 12 mL of deionized water). INTRODUCTION The total antioxidant activity can be measured by the The total antioxidant activity can be measured by the ferric reducing antioxidant power assay (FRAP ). Th e is depending on their potential to form the complex with metal atoms, particularly iron and copper. 2.2 Ferric ion reducing antioxidant power assay (FRAP) Ferric ions reducing power was measured according to the method of Oyaizu with a slightest ml of 20 mM phosphate buffer and 2.5 ml 1%, w/v potassium ferricyanide, and then the mixture was incubated at 50 C for 30 min. The reaction was terminated by adding 2.5 Antioxidant activity is determined as increase of absorbance at 593 nm, and results are expressed as micromolar Fe 2+ equivalents or relative FRAP assay stands for Ferric Reducing Antioxidant Power Assay. The FRAP assay is high-throughput, adaptable and can detect antioxidant capacities as low as 0.2 mM Fe 2+ equivalents. Table 1 lists some examples of the application of these assays in evaluating the antioxidant activity of coffee beans/brew. Strain of the Human Nutrition Research Group at the University of Ulster, Coleraine. Potassium ferricyanide is the chemical compound with the formula K 3 [Fe (CN) 6 ]. Materials and Methods Extraction and Purification of Compounds from Sargassam wightii The extraction of various compounds from FRAP assay is based on the ability of the compound to produce colour when the colourless Fe3+-TPTZ complex become blue in colour when TPTZ forms The samples were methanolic extract, different fractions (n-hexane, chloroform) and standard ascorbic acid. 3.6. In the FRAP assay, a measured sample of a test solution is mixed with a measured volume of freshly prepared working FRAP reagent. the accuracy of The two S. elaeagnifolium extracts under investigation had their reduction capacity assessed using the procedure outlined by Zovko Konci et al. Briefly, Reagents for FRAP assay a) Acetate buffer 300 mM pH 3.6: b) TPTZ (2, 4, 6-tripyridyl-s- triazine): (M.W. Solutions wwre kept at 50 oC for 20 mins. Potassium ferricyanide 1 % was prepared by dissolving 0.1 g of Potassium ferricyanide (Sigma) in 10 ml distilled water. The solution was kept in centrifuge tube and wrapped in an aluminium foil. Optimization of the antioxidant-rich xanthone extract from mangosteen (Garcinia mangostana L.) pericarp via microwave-assisted extraction. Briefly, 0.2 mL of each of the extracts at different concentrations, 2.5 mL of phosphate buffer (0.2 M, pH 6.6), and 2.5 mL of potassium ferricyanide K 3 Fe(CN) 6 (1%) were mixed and incubated at 50C for 20 min, to reduce ferricyanide into In the FRAP assay, a measured sample of a test solution is mixed with a measured volume of freshly prepared working FRAP reagent. The FRAP assay was first performed by Iris Benzie and J. J. 1996, 239, 7076. et alBanerjee . (2016) reported that essential oils extracted from parsley flowers by hydrodistillation exhibited antioxidant activity at 500, 1000, 2000, and 5000 mg/mL with the highest concentration exhibiting inhibition of DPPH radical at 64.28% and ferric reducing to chelate metal ions by FRAP assay. Reaction mechanism of 2,2-diphenyl-1-picrylhydrazyl (DPPH) with antioxidant. 2.6.3. estimated using the reducing power assay [9]. Iron(III)-based TAC assays, especially the most widely used FRAP (ferric-reducing antioxidant power), play an important role in this regard. About; potential by potassium ferricyanide and ABTS reduction assay. The ferric reducing anti-oxidant power (FRAP) assay involved the following steps: a) preparation of samples, b) reactions and c) finally measuring absorbance of sample and standard at 700 nm using spectrophotometer. The crude methanol and its fractionated extracts (hexane and ethyl acetate) were dissolved in methanol whilst the water extracts were dissolved in distilled water. Power Assay (FRAP) The reducing power of MEMCP was determined using the method reported by Oyaizu [16] but with slight (0.2 M, pH 6.6) and 2.5 mL of 1% potassium ferricyanide [K 3 Fe(CN) 6] solution. Firstly, Diphylleia grayi extract was mixed with 0.2 M sodium phosphate buffer (pH 6.6) and 1% Warm to room temperature before use. More recently, potassium ferricyanide has been the most common ferric reagent used in FRAP tests. Briefly, 0.2 mL of each of the extracts at different concentrations, 2.5 mL of phosphate buffer (0.2 M, pH 6.6), and 2.5 mL of potassium ferricyanide K 3 Fe(CN) 6 (1%) were mixed and incubated at 50C for 20 min, to reduce ferricyanide into Ferric reducing antioxidant power (FRAP) assay Reducing power of crude extract was determined by the method prescribed by Oyaizu[21]. Results are expressed in mM TE/g fresh mass. Aliquots (2.5 mL) of 10% trichloroacetic acid were added to the mixture. With authentically pure metallic cobalt and purified potassium ferricyanide. Use within two months. Yes, serum and plasma samples should be diluted 10-fold in dH 2 O prior assay. (e.g. This bright red salt contains the octahedrally coordinated [Fe (CN) 6] 3 ion. Store at 4C when not in use. The assay measures the antioxidant ability from all species. Briefly, 1.0 mL of extract was mixed with 2.5 mL of phosphate buffer (0.2 M, pH 6.6) and 2.5 mL potassium ferricyanide (1%). 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. Scientific Reports, Jun 2022 Share sensitive information only on official, secure websites. It is soluble in water and its solution shows some green-yellow fluorescence. Article. The different extracts of S. undulata were evaluated for their radical scavenging activities by means of the DPPH assay. FRAP. 5.5 FRAP Positive Control Aliquots (2.5 mL) of 10% trichloroacetic acid were added to the mixture. The ferric reducing ability of plasma (FRAP) as a measure of antioxidant power: The FRAP assay. The potassium ferricyanide assay is another type of FRAP method based on the reduction of Fe (III) to Fe (II), usually abbreviated as PFRAP. Molecules 2014, 19 19182 systems and end-point measures of primary lipid oxidation [4]. Potassium ferricyanide is the chemical compound with the formula K 3 [Fe (CN) 6 ]. The different extracts of S. undulata were evaluated for their radical scavenging activities by means of the DPPH assay. By Asgar Ali. Explain the principle on which the FRAP assay is based. Use this buffer for preparing kit reagents and within the assay. The absorbance of rind samples was collected at 570 nm spectrophotometer (UV-1800). Different concentrations of the sample (100-500 g) were taken in the test tubes and the volume in each test tube was made up to 0.1 ml with methanol. [Google Scholar] Berker, K.I. Quantity: 1 Quantity: 2 Quantity: 3 Quantity: 4 Quantity: 5 Quantity: 10 Quantity: 15 Quantity: 20 Quantity: 25. 5.3 FeCl3 Solution Ready to use as supplied. capacity of the leaves extracts using the FRAP Assay. BioAssay Systems' FRAP Assay Kit (DFRAP-250) measures antioxidant potential to reduce Fe3+ to Fe2+. The modification involved the simultaneous use of ferricyanide and iron(III) to regulate more favorable redox conditions for a greater variety of antioxidants. The essential oil or standard (Ascorbic acid and Trolox) was refrigerated at 4C until use. Further total phenolic and flavonoid contents of the crude fruit extract were also measured. The ferric reducing ability of plasma (FRAP) as a measure of antioxidant power: The FRAP assay. Total phenolic content (TPC) was determined by using Folin-Ciocalteu reagent based spectrophotometric assay with slight modifications. 5. 5.2 FRAP Probe Ready to use as supplied. Solutions wwre kept at 50 oC for 20 mins. FRAP. 5. Optimization of the antioxidant-rich xanthone extract from mangosteen (Garcinia mangostana L.) pericarp via microwave-assisted extraction. Explain the principle on which the FRAP assay is based. Keep on ice while in use. estimated using the reducing power assay [9]. assay that used or employed colorimetry as end product determination are as follow : 2,2-diphenyl-l picrylhydrazyl (DPPH), 2,2'-azino-bis(3 ethylbenzothiazoline-6-sulphonic acid) (ABTS), ferric reducing antioxidant power (FRAP) method, potassium ferricyanide reducing power (PFRAP) method, and cupric Antioxidant activity is determined as increase of absorbance at 593 nm, and results are expressed as micromolar Fe 2+ equivalents or relative Potassium ferricyanide (1%, w/v) and ferric chloride (0.2%, w/v) solutions were prepared as described in Original Ferricyanide Assay of Reducing Power section. General description. Potassium ferricyanide + Ferric chloride Potassium ferrocyanide + Ferrous chloride Chemicals required Potassium ferricyanide (1% w/v), phosphate buffer (0.2 M, pH 6.6), trichloro acetic acid (10%), ferric chloride (0.1%) and ascorbic acid (1%).