Dipstick for enzyme immuno:assay not requiring washing step - includes test zone contg. capture reagent forming complex with analyte and enzyme labelled antibody, opt. also enzyme inhibitor and poly:ol

摘要

Dipstick for immunoassays comprises (1) a base (112); (2) at least one test zone (110) on the base and (3) at least one immobilised, immunologically active component (I) distributed in zone (110) in the form of a specific symbol. (I) can bind an enzyme labelled antibody (176), via a target analyte (A), so as to form a sandwich complex on zone (110). This complex, after contact with a suitable enzyme substrate, will produce a difference between the specified symbol and the rest of the test zone which can be detected by the eye. Also new is a kit comprising, apart from the dipstick, a soln. of Ab and a soln. of substrate which generates an insoluble coloured product in contact with Ab. (I) is an antigen, hapten or antibody. The base is made of plastic or glass, and the test zone of nylon, (nitro)cellulose, fibre glass, polysulphone poly(vinylidene fluoride) or polyester. The reaction zone may also include an enzyme inhibitor (II; not in the region representing the symbol) and a polyol (III). USE/ADVANTAGE - This device obviates the need for a washing step generally required in dipstick assays, and can be used successfully by relatively untrained personnel. It can be used to assay antibodies, antigens or haptens, or for gene screening and for detection of genetic sequences (using immobilised complementary seuqences and labelled nucleii acid probes). The presence of (II) and (III) intensifies the colour difference between symbol and the rest of the zone.