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F9252

Sigma-Aldrich

Folin & Ciocalteu′s phenol reagent

suitable for determination of total protein by Lowry method, 2 N

MDL number:
NACRES:
NA.47

form

liquid

Quality Level

concentration

2 N

color

clear yellow

pH

<0.5 (20 °C)

density

1.240 g/cm3 at 20 °C

suitability

suitable for determination of total protein by Lowry method

application(s)

diagnostic assay manufacturing
hematology
histology

storage temp.

room temp

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General description

Folin & Ciocalteu′s phenol reagent is most commonly used in the Lowry method for determining protein concentration. It has also been used for the quantification of total phenolics. In this method, protein is pretreated with copper(II) in a modified biuret reagent (alkaline copper solution
stabilized with sodium potassium tartrate). Addition of the phenol reagent generates chromogens that give increasing absorbance between 550-750nm. Normally, absorbance at the peak (750nm) or shoulder (660nm) are used to quantitate protein concentrations between 1-100 mg/ml while absorbance at 550nm is used to quantitate higher protein concentrations.
In the absence of copper, color intensity is determined primarily by the tyrosine and tryptophan content of the protein, and to a lesser extent by cysteine and histidine. Copper(II) has no effect on color formation by tyrosine, tryptophan, or histidine, but reduces color formation due to cysteine.
Many modifications of the original assay procedure have been published, including methods for enhancing the color development, for determining the content of insoluble proteins, and for automating the procedure. Compounds including many buffers, chelating agents, detergents, and cyclic organic compounds can interfere with the Lowry protein assay.
Folin & Ciocalteu′s phenol reagent can also be used as a spray reagent in chromatographic procedures.

Application

Folin & Ciocalteu′s phenol reagent has been used for the estimation of total phenolic content in samples.

Packaging

1 L in glass bottle
100, 500 mL in glass bottle

Other Notes

Folin & Ciocalteu′s phenol reagent does not contain phenol. Rather, the reagent will react with phenols and non-phenolic reducing substances to form chromogens that can be detected spectrophotometrically.

Linkage

This product is also available as part of a kit.

Pictograms

Corrosion

Signal Word

Danger

Hazard Statements

Hazard Classifications

Eye Dam. 1 - Met. Corr. 1 - Skin Corr. 1

Storage Class Code

8B - Non-combustible, corrosive hazardous materials

WGK

WGK 1

Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Certificate of Analysis

Enter Lot Number to search for Certificate of Analysis (COA).

Certificate of Origin

Enter Lot Number to search for Certificate of Origin (COO).

  1. What concentrations of proteins does Product F9252, Folin & Ciocalteu's phenol reagent, detect?

    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.

  2. Can Product F9252, Folin & Ciocalteu's phenol reagent, be used to detect any protein?

    If the protein has an abnormally low tyrosine content, this method would not be suitable.

  3. What should Product F9252, Folin & Ciocalteu's phenol reagent, look like?

    The Folin & Ciocalteu's phenol reagent should be a clear yellow solution.  If the solution turns green, it may not be suitable and it should not be used.

  4. Does Product F9252, Folin & Ciocalteu's phenol reagent, contain phenol?

    The Folin & Ciocalteu's phenol reagent does not contain phenol but reacts with phenol and non-phenolic reducing substances to form chromogens that can be detected spectrophotometrically.

  5. Which document(s) contains shelf-life or expiration date information for a given product?

    If available for a given product, the recommended re-test date or the expiration date can be found on the Certificate of Analysis.

  6. How do I get lot-specific information or a Certificate of Analysis?

    The lot specific COA document can be found by entering the lot number above under the "Documents" section.

  7. How do I find price and availability?

    There are several ways to find pricing and availability for our products. Once you log onto our website, you will find the price and availability displayed on the product detail page. You can contact any of our Customer Sales and Service offices to receive a quote.  USA customers:  1-800-325-3010 or view local office numbers.

  8. What is the Department of Transportation shipping information for this product?

    Transportation information can be found in Section 14 of the product's (M)SDS.To access the shipping information for this material, use the link on the product detail page for the product. 

  9. My question is not addressed here, how can I contact Technical Service for assistance?

    Ask a Scientist here.

Bioactive compounds and antioxidant activities during fruit ripening of watermelon cultivars.
Tlili I et al.
J. Food Compos. Anal., 24, 923-928 (2011)
E Larson et al.
Analytical biochemistry, 155(2), 243-248 (1986-06-01)
Addition of dithiothreitol in the Lowry procedure 3 min after adding the Folin-Ciocalteau reagent produces immediate color development, with 35 to 60% greater absorbance per mass of protein used.
Analysis of phenolic compounds of interest in metabolism.
H G BRAY et al.
Methods of biochemical analysis, 1, 27-52 (1954-01-01)
Lowry's method of protein estimation: some more insights.
S Sengupta et al.
The Journal of pharmacy and pharmacology, 45(1), 80-80 (1993-01-01)
Nutritional evaluation of some subtropical red and green seaweeds Part II. In vitro protein digestibility and amino acid profiles of protein concentrates.
Wong KH and Cheung PCK
Food Chemistry, 72, 11-17 (2001)

Articles

Enzymatic Assay of Proteinase K with Hemoglobin Substrate

Proteinase K (EC 3.4.21.64) activity can be measured spectrophotometrically using hemoglobin as the substrate. Proteinase K hydrolyzes hemoglobin denatured with urea, and liberates Folin-postive amino acids and peptides. One unit will hydrolyze hemoglobin to produce color equivalent to 1.0 μmol of tyrosine per minute at pH 7.5 at 37 °C (color by Folin & Ciocalteu's Phenol Reagent).

Protocols

Protein Determination Modified Lowry Method

To standardize a procedure for the determination of protein by modified Lowry.

Universal Protease Activity Assay: Casein as a Substrate

Proteases break peptide bonds. In the lab, it is often necessary to measure and/or compare the activity of proteases. Sigma's non-specific protease activity assay may be used as a standardized procedure to determine the activity of proteases, which is what we do during our quality control procedures.

Enzymatic Assay of Proteinase K (EC 3.4.21.64)

Proteinase K (EC 3.4.21.64) activity can be measured spectrophotometrically using hemoglobin as the substrate. Proteinase K hydrolyzes hemoglobin denatured with urea, and liberates Folin-postive amino acids and peptides. One unit will hydrolyze hemoglobin to produce color equivalent to 1.0 μmol of tyrosine per minute at pH 7.5 at 37 °C (color by Folin & Ciocalteu's Phenol Reagent).

Enzymatic Assay of Protease Using Casein As a Substrate

To standardize a procedure for the enzymatic assay of Protease using Casein as a substrate.

Related Content

Tools for Protein Quantitation

A wide variety of products for traditional protein quantitation techniques such as BCA and Bradford. Also, products for alternative assays such as Lowry, Micro Pyrogallol and FluoroProfile are also available for total protein determination.

Our team of scientists has experience in all areas of research including Life Science, Material Science, Chemical Synthesis, Chromatography, Analytical and many others.

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