Folin reaction

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Fo·lin re·ac·tion

(fol'-in),
the reaction of amino acids in alkaline solution with 1,2-naphthoquinone-4-sulfonate (Folin reagent) to yield a red color; useful for quantitative assay.
Synonym(s): Folin reagent
[O. K. O. Folin]

Fo·lin re·ac·tion

(fō'lin rē-ak'shŭn)
The reaction of amino acids in alkaline solution with 1,2-naphthoquinone-4-sulfonate (Folin reagent) to yield a red color; useful for quantitative assay.
[O. K. O. Folin]

Folin,

Otto K.O., U.S. biochemist, 1867-1934.
Folin reaction - the reaction of amino acids in alkaline solution with 1,2-naphthoquinone-4-sulfonate (Folin reagent) to yield a red color. Synonym(s): Folin reagent
Folin reagent - Synonym(s): Folin reaction
Folin test - a quantitative test for urea.
Folin-Looney test - a test for tyrosine that gives a blue color in alkaline solution with a reagent consisting of sodium tungstate, phosphomolybdic acid, and phosphoric acid.
Lowry-Folin assay - Synonym(s): Lowry protein assay
References in periodicals archive ?
Then 1.0 mL Folin reagent and 2.0 mL saturated solution of sodium carbonate (NaCO3) were also added to it [10].
An aliquot of 200 [micro]L of seminal fluid was mixed with 0.25 mL of Folin reagent and 0.5 mL saturated solution of sodium carbonate.
The final step isadd 1 ml Folin reagent and incubated for 20 min at 55[degrees]C until color developed the green color was measured at 660 nm wavelength.
Gallic acid, sodium carbonate and Folin reagent, Trolox (6-hydroxy- 2,5,7,8tetramethylchroman carboxylic acid), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid acid) diammonium salt (ABTS), 2,2-diphenyl-1-pycrylhydrazil were purchased from SigmaAldrich (St.Louis MO).
According to the reaction mechanism these assays are divided into two broad categories: Hydrogen atom transfer assay (HAT) such as inhibition of induced LDL auto-oxidation, oxygen radical absorbance capacity (ORAC), total radical trapping antioxidant parameter (TRAP), crocin bleaching assays and electron transfer assay (ETA) that includes the TPC assay by the Folin reagent, Trolox equivalence antioxidant capacity (TEAC), ferric ion (Fe3+) reducing antioxidant power (FRAP), "total antioxidant potential" assay where Cu(II) complex captures electrons, and DPPH assay.
After 10 minutes 0.3 ml of Folin reagent was further added followed by a vigorous shaking immediately.
Samples were performed in the dark to prevent degradation of the Folin reagent. The spectrophotometric absorbance was converted to protein concentration using a calibration curve [8].
In short, 0.5 ml of crude extract of each fraction (1 mg/mL) of plant was mixed with 0.5 mL of Folin-ciocalteu reagent (1 mL folin reagent + 4 mL distill water) and 7.5 mL deionized water and the mixture was kept for 10 min at room temperature, and then added 1.5 mL 20% sodium carbonate (w/v), mixed it thoroughly.