Reagents

摘要

An immunological reagent is produced by treating an aqueous suspension of mammalian red blood cells, with a mordant, an aldehyde and a protein antigen wherein the mordant is a polyphenol or quinone of M.W. under 200. The molar ratio of mordant to aldehyde may be between 1 : 5 and 1 : 150. The cells may first treated with the mordant, next the aldehyde and then with the antigen although satisfactory results may be obtained by adding the aldehyde before the mordant or a mixture of aldehyde and mordant. It may be necessary to have a buffer present to minimise any fall of pH occuring on mixing the mordant with the aldehyde e.g. by using a phosphate buffer. The mordant may be a hydroquinone (a cross-conjugated aromatic diol capable of oxidation to quinones) e.g. toluene-2, 5 -diol, naphthalene-1, 4-and -2, 6-diols but preferable benzene-1, 4-diol. In addition the corresponding quinones and other benzene, toluene and naphthalene diols may be used. The antigens exemplified are chorionic gonadotropin (HCG), g -globulin and bovine serum albumin. The red cells used are conveniently those obtained from sheep but cells of other mammalian species including the ox, horse, rabbit and man may be used. Specific examples of process to yield HCG and g -globulin sensitized cells as in Specification 1,036,591 are given together with buffer solutions suitable for use in these processes. This reagent can be used to detect protein antigens for example in body fluids, among such antigens are chorionic gonodotropin (HCG), (HCG), serum albumin, g -globulin, insulin, tetanus toxoid and diptheria toxoid. When used to detect HCG in pregnancy urine, the reaction forms the basis of an in vitro test for pregnancy and such an application is disclosed.