| uric acid | <biochemistry> The final product of nitrogenous excretion in animals that require to conserve water, such as terrestrial insects or have limited storage space, such as birds and their eggs. Uric acid has very low water solubility and crystals may be deposited in, for example: butterflies wings to impart irridescence. Uric acid, a crystalline body, present in small quantity in the urine of man and most mammals. Combined in the form of urate of ammonia, it is the chief constituent of the urine of birds and reptiles, forming the white part. Traces of it are also found in the various organs of the body. It is likewise a common constituent, either as the free acid or as a urate, of urinary or renal calculi and of the so-called gouty concretions. From acid urines, uric acid is frequently deposited, on standing in a cool place, in the form of a reddish yellow sediment, nearly always crystalline. Chemically, it is composed of carbon, hydrogen, nitrogen, and oxygen, and by decomposition yields urea, among other products. It can be made synthetically by heating together urea and glycocoll. It was formerly called also lithic acid, in allusion to its occurrence in stone, or calculus. See: tophus. Structure: C5H4N4O3 Source: Websters Dictionary (18 Nov 1997) |
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| uric acid infarct | <nephrology, paediatrics> Precipitates of uric acid distending renal collecting tubules in the newborn; since there is no necrosis, the term infarct is a misnomer. (20 Jun 2000) |
| uric acid oxidase | <enzyme> An enzyme that catalyses the conversion of urate and unidentified products. It is a copper protein. The initial products decompose to form allantoin. Chemical name: Urate:oxygen oxidoreductase Registry number: EC 1.7.3.3 (12 Dec 1998) |
| uric | <nephrology> Of or pertaining to urine, obtained from urine. For example; uric acid. Origin: G. Ouron, urine (20 Jun 2000) |
| amino acid reagent | A reagent used in the identification and quantification of amino acids. (05 Mar 2000) |
| Benedict-Hopkins-Cole reagent | <chemistry> Magnesium glyoxalate, made from a mixture of oxalic acid and magnesium, used for testing proteins for the presence of tryptophan. (12 Aug 2000) |
| biuret reagent | An alkaline solution of copper sulfate. (05 Mar 2000) |
| Mandelin's reagent | A solution of ammonium vanadate in sulfuric acid, used in colour tests for alkaloids. (05 Mar 2000) |
| reagent | <technique> A histochemical technique based on periodic acid oxidation of a substance containing the 1,2-glycol grouping. It is used for staining carbohydrates as the resulting dialdehyde reacts with Schiff reagent to form a coloured product. The adjacent hydroxyl groups are oxidized to form aldehydes by periodic acid (HIO4) and these aldehyde groups react with Schiff's reagent (basic fuchsin decolourised by sulphurous acid) to give a purple colour. Acronym: PAS (18 Nov 1997) |
| reagent kits, diagnostic | Commercially prepared reagent sets, with accessory devices, containing all of the major components and literature necessary to perform one or more designated diagnostic tests or procedures. They may be for laboratory or personal use. (12 Dec 1998) |
| reagent strips | Narrow pieces of material impregnated or covered with a substance used to produce a chemical reaction. The strips are used in detecting, measuring, producing, etc., other substances. (12 Dec 1998) |
| Marme's reagent | A solution of potassium iodide and cadmium iodide used in testing for alkaloids. (05 Mar 2000) |
| Marquis' reagent | A solution of formaldehyde in sulfuric acid used in colour tests for formaldehyde. (05 Mar 2000) |
| Girard's reagent | The hydrazine of betaine chloride, used to extract ketonic steroids by forming water-soluble hydrazones with them. (05 Mar 2000) |
| Mecke's reagent | A solution of selenous acid in sulfuric acid, used for colour tests of alkaloids. (05 Mar 2000) |