What is the role of Folin-Ciocalteu reagent in protein estimation?

What is the role of Folin-Ciocalteu reagent in protein estimation?

Generally, Folin & Ciocalteu’s phenol reagent is used to determine protein concentrations between 1 to 100 μg/mL. However, the reagent exhibits a linear response to protein concentration up to 1000 μg/mL when used according to the instructions for kit Product No. TP0200.

What does Folin-Ciocalteu reagent contain?

The Folin-Ciocalteu (F-C) Assay was developed in 1927 for the measurement of tyrosine (1). The reagent consists of a mixture of sodium molybdate, sodium tungstate and other reagents. Upon reaction with phenols, it produces a blue color which absorbs at 765 nm.

How is estimation of protein done using Folin Lowry method?

The principle behind the Lowry method of determining protein concentrations lies in the reactivity of the peptide nitrogen[s] with the copper [II] ions under alkaline conditions and the subsequent reduction of the Folin- Ciocalteay phosphomolybdic phosphotungstic acid to heteropolymolybdenum blue by the copper- …

What is the role of Folin-Ciocalteu reagent in Lowry method?

Lowry adds phosphomolybdic/phosphotungstic acid also known as Folin-Ciocalteu reagent. This reagent interacts with the cuprous ions and the side chains of tyrosine, tryptophan, and cysteine to produce a blue-green color that can be detected between 650 nm and 750 nm. The protein detection range is 5–100 μg.

What is the full form of FC reagent?

The Folin–Ciocâlteu reagent (FCR) or Folin’s phenol reagent or Folin–Denis reagent, also called the gallic acid equivalence method (GAE), is a mixture of phosphomolybdate and phosphotungstate used for the colorimetric in vitro assay of phenolic and polyphenolic antioxidants.

How do you do protein estimation?

The modified Lowry method is a combination of the Biuret method, where copper ions react with the peptide bonds within the protein, and a reaction between Folin-Ciocalteu reagent and the ring structure on aromatic amino acids. The total reaction forms a stable, dark blue complex that can be read at 650–750 nm [3].

Why gallic acid is used as standard?

Gallic acid was used as the standard for the estimation of phenolics. The extract having the highest phenolic content showed the lowest IC50 demonstrating the positive correlation between radical scavenging activity and total phenolic content.

How do you dilute Folin-Ciocalteu reagent?

Folin-Ciocalteu reagent (1 N): Dilute commercially available Folin-Ciocalteu reagent (2 N) with an equal volume of distilled water. Transfer it in a brown bottle and store in a refrigerator (4°C). It should be golden in colour. Do not use it if it turns olive green.

What is a Folin test?

Folin’s reagent or sodium 1,2-naphthoquinone-4-sulfonate is a chemical reagent used as a derivatizing agent to measure levels of amines and amino acids. The reagent reacts with them in alkaline solution to produce a fluorescent material that can be easily detected.

Why do we do protein estimation?

Protein quantification is necessary to understand the total protein content in a sample or in a formulated product. Accurate protein quantification is important as a range of other critical assays require precise total protein content results in order to generate data.

What kind of reagent is Folin-Ciocalteau method?

The Folin–Ciocalteu reagent (FCR) or Folin’s phenol reagent or Folin–Denis reagent, also called the Gallic Acid Equivalence method (GAE), is a mixture of phosphomolybdate and phosphotungstate used for the colourimetric in vitro assay of phenolic and polyphenolic antioxidants.

How to calculate the volume of tyrosine by Folin Ciocalteau?

Take 0.2, 0.4, 0.6, 0.8 and 1ml into series if five test tubes add water to bring the volume of one ml in each test tube. Add 5ml of 0.5N NaOH solution and finally 1.5ml of dilute F/C reagent to each test tube mix well and measure the O.D. with a photoelectric colourimeter at 700nm (or) by using a red filter within 2 to 10 minutes.

What is the dilution ratio for BSA and Folin?

• At the protocol given by Gerhardt et al. (1994), the dilution ratio for the Folin and Ciocalteu’s Phenol Reagent is 1:1, resulting in a 1N Folin reagent. Although BSA is a water-soluble protein, it takes time to dissolve it completely.

How to make an accurate determination of protein concentration?

To make an accurate determination of protein concentration, you will have to produce a standard curve (A280) with known amounts of purified protein. You will also have to provide a blank that is appropriate for the sample and contains the same concentrations of buffer and salts as the sample.