Reagent
A substance used to produce a chemical reaction to detect, measure, produce, etc. other substances.
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Any substance added to a solution of another substance to participate in a chemical reaction. [Mod. L. reagens]
- amino acid r. a r. used in the identification and quantification of amino acid s.
- Benedict-Hopkins-Cole r. magnesium glyoxalate, made from a mixture of oxalic acid and magnesium, used for testing proteins for the presence of tryptophan.
- diazo r. two solutions, one of sodium nitrite, the other of acidified sulfanilic acid, used in bringing about diazotization. SYN: Ehrlich diazo r..
- Dische r. Dische reaction.
- Dische-Schwarz r. r. used in the colorimetric detection of RNA.
- Drabkin r. a solution used in the cyanmethemoglobin method of measuring hemoglobin. It consists of sodium bicarbonate, potassium cyanide, and potassium ferricyanide.
- Dragendorff r. a r. used in the detection of alkaloids.
- Ehrlich diazo r. SYN: diazo r..
- Erdmann r. a mixture of sulfuric and nitric acid s, used in testing alkaloids.
- Esbach r. picric acid, citric acid, and water (in the proportions 1, 2, and 97) used for the detection of albumin in the urine.
- Exton r. 50 g of sulfosalicylic acid and 200 g of Na2SO4 10H2O in a liter of water, used as a test for albumin.
- Fehling r. SYN: Fehling solution.
- Folin r. SYN: Folin reaction.
- Fouchet r. a 25% solution of trichloroacetic acid, containing 0.9% ferric chloride; a drop of the r. added at the surface line of barium chloride-impregnated filter paper that has been dipped in urine for 10 s will give a green color if bilirubin is present. SEE ALSO: Fouchet stain.
- Froehde r. sodium molybdate in strong sulfuric acid; this r. gives various color reactions with alkaloids.
- Frohn r. bismuth subnitrate (1.5) and water (20.0) heated to boiling, to which hydrochloric acid (10.0) and potassium iodide (7.0) are added; used to test for alkaloids and for sugar.
- Girard r. the hydrazine of betaine chloride, used to extract ketonic steroids by forming water-soluble hydrazones with them.
- Günzberg r. phloroglucin and vanillin used as a r. in Günzberg test.
- Hahn oxine r. an alcoholic solution of 8-hydroxyquinoline used in the determination of zinc, aluminum, magnesium, and other minerals.
- Hammarsten r. a mixture of 1 part 25% solution of nitric acid and 19 parts 25% solution of hydrochloric acid; the addition of a few drops to a mixture of 1 part of this r. and 4 parts alcohol will give a green color if bile is present.
- Ilosvay r. sulfanilic acid 0.5, dissolved in dilute acetic acid 150, mixed with naphthylamine 1, and dissolved in boiling water 20; the blue sediment that forms is dissolved in dilute acetic acid 150; a few drops of this r. added to water, saliva, or other fluid to be tested will produce a red color if nitrites are present.
- Kasten fluorescent Schiff reagents fluorescent analogs of Schiff r. that are fluorescent basic dyes lacking acidic side groups and containing one or more primary amine groups; used in cytochemical detection of DNA in Kasten fluorescent Feulgen stain, polysaccharides in Kasten fluorescent PAS stain, and proteins in the ninhydrin-Schiff stain; such analogs include acriflavine, auramine O, and flavophosphine N.
- Lloyd r. precipitated aluminum silicate, used in the determination of alkaloids.
- Mandelin r. a solution of ammonium vanadate in sulfuric acid, used in color tests for alkaloids.
- Marme r. a solution of potassium iodide and cadmium iodide used in testing for alkaloids.
- Marquis r. a solution of formaldehyde in sulfuric acid used in color tests for formaldehyde.
- Mecke r. a solution of selenous acid in sulfuric acid, used for color tests of alkaloids.
- Meyer r. a solution of phenolphthalein with sodium hydroxide, in water (glass-distilled); in the presence of minute traces of blood, the solution becomes purple or blue-red.
- Nessler r. a solution of potassium hydroxide, mercuric iodide, and potassium iodide; it yields a yellow color with ammonia (a brown precipitate with larger amounts) that can be used for quantitative assay.
- Rosenthaler-Turk r. a solution of potassium arsenate in sulfuric acid used in obtaining color tests for various opium alkaloids.
- Sanger r. SYN: fluoro- 2,4-dinitrobenzene.
- Schaer r. an alcoholic or aqueous solution of chloral hydrate used as an extraction medium in investigations of alkaloids.
- Scheibler r. a solution of sodium tungstate in phosphoric acid used in tests for alkaloids.
- Schiff r. an aqueous solution of basic fuchsin or pararosaniline that is decolorized by sulfur dioxide, commonly prepared by addition of hydrochloric acid to a dye solution containing a metabisulphite or bisulphite salt; used for aldehydes and in histochemistry to detect polysaccharides, DNA, and proteins. See Feulgen stain, periodic acid -Schiff stain, ninhydrin-Schiff stain for proteins.
- Scott-Wilson r. an alkaline solution of mercuric cyanide and silver nitrate used in the detection of acetone.
- sulfhydryl r. r. that reacts with thiol groups, particularly those in proteins.
- Sulkowitch r. a r. for the detection of calcium in the urine, consisting of 2.5 g of oxalic acid, 2.5 g of ammonium oxalate, 5 mL of glacial acetic acid, and distilled water to make 150 mL; a milky precipitate of calcium oxalate is formed when the r. is added to urine that contains calcium.
- Uffelmann r. a solution prepared by adding a 2% solution of phenol in water to aqueous ferric chloride until the solution becomes violet in color; this turns lemon yellow in the presence of lactic acid, assumes an opaline tint in butyric acid, and is decolorized by hydrochloric acid.
- Wurster r. filter paper impregnated with tetramethyl-p-phenylenediamine, which turns blue in the presence of ozone or hydrogen peroxide.

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re·agent rē-'ā-jənt n
1) a substance used (as in detecting or measuring a component, in preparing a product, or in developing photographs) because of its chemical or biological activity
2) REACTOR (1b)

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re·a·gent (re-aґjənt) [re- + agent] a substance employed to produce a chemical reaction so as to detect, measure, produce, etc., other substances.

Medical dictionary. 2011.

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  • Reagent — Re*a gent (r[ e]*[=a] jent), n. (Chem.) A substance capable of producing with another a reaction, especially when employed to detect the presence of other bodies; a test. [1913 Webster] …   The Collaborative International Dictionary of English

  • reagent — REAGÉNT s. v. agent chimic, reactiv. Trimis de siveco, 05.08.2004. Sursa: Sinonime …   Dicționar Român

  • reagent — (n.) 1797, from RE (Cf. re ) + AGENT (Cf. agent) substance that produces a chemical reaction …   Etymology dictionary

  • reagent — ► NOUN ▪ a substance or mixture for use in chemical analysis or other reactions …   English terms dictionary

  • reagent — [rē ā′jənt] n. [ RE + AGENT] Chem. a substance used to detect or measure another substance or to convert one substance into another by means of the reaction which it causes …   English World dictionary

  • Reagent — Reagents, such as sulfur (pictured), are the starting materials that are used in chemical reactions. A reagent is a substance or compound that is added to a system in order to bring about a chemical reaction or is added to see if a reaction… …   Wikipedia

  • reagent — UK [rɪˈeɪdʒ(ə)nt] / US [rɪˈeɪdʒənt] noun [countable] Word forms reagent : singular reagent plural reagents chemistry a substance used in a chemical reaction …   English dictionary

  • reagènt — ênta in énta m (ȅ é, ẹ) kem. snov, s katero se po značilnih reakcijah ugotavljajo vrste sestavin kake snovi: dodati raztopini reagent / kemični reagenti ♦ mont. flotacijski reagent ki se pri flotaciji dodaja vodi …   Slovar slovenskega knjižnega jezika

  • reagent — cheminis reagentas statusas T sritis chemija apibrėžtis Grynas cheminis junginys, griežtai nustatytos sudėties mišinys ar tirpalas, vartojamas analizei ir tyrimams. atitikmenys: angl. chemical reagent; reagent rus. реагент; реактив; химический… …   Chemijos terminų aiškinamasis žodynas

  • reagent — noun Etymology: New Latin reagent , reagens, present participle of reagere to react more at react Date: 1797 a substance used (as in detecting or measuring a component, in preparing a product, or in developing photographs) because of its chemical …   New Collegiate Dictionary

  • reagent — [[t]rie͟ɪʤənt[/t]] reagents N COUNT A reagent is a substance that is used to cause a chemical reaction. Reagents are often used in order to indicate the presence of another substance. [TECHNICAL] …   English dictionary

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