Detection and determination of haptens

Claim 1

Process for the detection and determination of a hapten being a protein-free substance which is not capable of stimulating antibody formation but which reacts with antibodies by means of a binding protein capable of reacting to bind said hapten specifically, comprising the steps of: a. providing a given quantity of the coupling product of said hapten and an enzyme; b. providing a corresponding given quantity of a specific binding protein capable of reacting to bind said hapten and said hapten-enzyme coupling product and being an antibody produced by injecting the coupling product of the hapten and a high molecular substance capable of stimulating antibody formation into the blood of an animal and subsequently isolating the antibody from the animal blood; c. the nature of the coupling in the coupling product of the hapten and enzyme and the coupling product of the hapten and high molecular substance being chemically different as a result of either (a) a chemically different bond or bridge, (b) chemically different haptens which are immunologically related, (c) coupling via another position of the hapten molecule, or (d) combinations of (a), (b) and (c); d. contacting a sample of a fluid containing the hapten to be determined with said coupling product of the hapten and enzyme and said binding protein to form a reaction mixture; e. separating the hapten-enzyme coupling product bound to the binding protein from the unbound hapten-enzyme coupling product; and f. determining the enzyme activity of a separated portion, which activity is a measure of the quantity of hapten to be determined.