GB955719A - Quantitative glucose diagnostic composition - Google Patents

Abstract

A diagnostic composition for glucose comprises an enzyme having glucose oxidase activity, a substance having peroxidative activity, a primary indicator which is oxidized with colour change in the presence of peroxide and said peroxidative substance and a secondary indicator which reduces said primary indicator when in oxidized form but is not itself oxidized in the presence of peroxide and said peroxidative substance. Specified peroxidative substances are horseradish and potato peroxidases; normal whole blood, lyophilized whole blood, red blood cells, lyophilized red blood cells and a mixture of lyophilized blood and lyophilized plasma; potassium, sodium or ammonium iodide plus sodium, potassium or ammonium molybdate; urohemin, hemin and metalloporphyrins which are not operable per se plus activating 2-aminobenzthiazole, pyridine, bipyridyl, bipyridil pyridine or nicotinic acid; and iron sulphocyanate, iron tannate, ferrous ferrocyanide and potassium chromic sulphate. Primary indicators specified are: o-tolidine, 2 : 7-diaminofluorine, o-dianisidine and leucoindophenols. Secondary indicators specified are: dl-b -(3 : 4-dihydroxyphenyl) alanine, chlorpromazine hydrochloride, 2 : 4-dinitrophenol, N : N-dimethyl-p-phenylene diamine, 3 : 31-diaminobenzidine and p-aminodimethylaniline. More than one primary or secondary indicator may be present and in one example p-aminobenzoic acid is also present: it is stated that p-nitrophenol also functions to reduce the oxidized indicator. In the examples, there are also present: gelatin, buffer components (citrate, phosphate), polyvinyl alcohol, and ethyl alcohol. The formulation is prepared as a solution which is impregnated into a bibulous material or may be in tablet or powder form. Specifications 575,612, 784,584, 808,742, 831,804, 843,221, 855,013, 880,526, 883,744 and 886,778 are referred to.