GB1039337A - Diagnostic composition and method - Google Patents

Abstract

Diagnostic compositions for detecting galactose, e.g. in urine, comprise galactose oxidase, a substance having peroxidative activity, an indicator changing colour in the presence of the latter substance and the reaction product of galactose with oxygen in the presence of galactose oxidase, and a polycarboxylic acid salt of tris-(hydroxymethyl)-aminomethane, said salt being present in a quantity such as to provide a pH of 5.8-7.5 for the test. The peroxidative substance may be peroxidase obtained from horseradish, potatoes, figtree sap, turnips or white blood corpuscles, or may be haemin, methaemoglobin, oxyheamoglobin, haemoglobin, haemochromogen, alkaline haematin and other haemin derivatives. The indicator may be gum guaiac, o-tolidine, 2 : 7-diaminofluorene, o-dianisidine, or leucoindophenols. Suitable buffering salts are glutamates, phthalates, malonates and citrates of the tris-(hydroxymethyl)-aminomethane. Other components which may be included in the compositions include thickening agents (polyvinyl alcohol, gelatin, bovine serum albumin, polyvinyl pyrrolidone, starch or sodium alginate) and wetting agents (dioctyl sodium succinate and polyoxyethylene sorbitan monooleate) and in examples, potassium chloride, and a yellow dye are referred to. The compositions may be in the form of a solution, or as tablets, fibres or adsorbent columns or as test strips of impregnated bibulous cellulose ion exchangers.