- * * *Any substance added to a solution of another substance to participate in a chemical reaction. [Mod. L. reagens]- 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..- Drabkin r. a solution used in the cyanmethemoglobin method of measuring hemoglobin. It consists of sodium bicarbonate, potassium cyanide, and potassium ferricyanide.- Ehrlich diazo r. SYN: diazo r..- 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.- 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.- 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.- 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.- Schaer r. an alcoholic or aqueous solution of chloral hydrate used as an extraction medium in investigations of 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.- 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.
* * *re·agent rē-'ā-jənt n1) a substance used (as in detecting or measuring a component, in preparing a product, or in developing photographs) because of its chemical or biological activity2) REACTOR (1b)
* * *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.
Look at other dictionaries:
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