Abstract: Reversibly inhibited antibodies are disclosed, suitable for treatment of diseases such as cancer. The reversibly inhibited antibodies are such that they regain their activity on illumination, for example with UV light. Compositions containing such antibodies, methods of preparation of such antibodies and methods of use of such antibodies are also disclosed. The moiety employed to provide reversible inhibition may comprise a hydrophilic polymer such as polyethylene glycol.

Abstract: A method of determining a hapten which comprises: (1) contacting the sample which contains or may contain the hapten with a first binding partner which binds the hapten; (2) separating the hapten bound to the first binding partner from material which is not bound by the first binding partner; (3) contacting the hapten bound to the first binding partner with a second binding partner which binds the hapten; and (4) assaying the hapten bound to a binding partner as is described. Kits are also described.

Abstract: A method is described for determining a hapten which method comprises (i) contacting the hapten with a binding partner of the hapten, whereby the hapten becomes bound to some of the binding partner, (ii) contacting the unbound binding partner with a secondary binding partner therefor, (iii) contacting the binding partner with an antibody which binds the binding partner which has bound thereto the hapten but which does not bind the binding partner which has bound thereto its secondary binding partner; and (iv) determining the amount of antibody bound to the binding partner. Kits for use in the method are also described.

Abstract: A secondary antibody capable of stabilizing the binding of a small molecule to its binding protein is described which secondary antibody is capable of binding said binding protein in the presence of an in the absence of the small molecule but is not capable of binding said small molecule in the absence of binding protein. Such antibodies may be obtained by forming a complex between a small molecule and its binding protein, using the complex to raise antibodies and selecting the antibodies. The antibodies may be used in competitive assays in which it is desired to improve the binding of a small molecule or labelled small molecule to its binding protein.

Abstract: A secondary monoclonal antibody against a complex of a molecule of molecular weight less than 5000 and a binding protein against said molecule which secondary monoclonal antibody is not an antibody against molecule or against its binding protein.

Abstract: The invention involves polyclonal antibodies reactive with a complex of a hapten and its binding protein, wherein the antibodies are unreactive with the free hapten or free binding protein. The antibodies are useful in assays of the hapten or the binding protein.

Abstract: Enzymatic assays are described which enable the detection of inter alia enzymes, cofactors and substrates in small quantity with the ability to produce a visually detectable change.

Abstract: An immunoassay uses an antibody or antigen -enzyme conjugate which converts a precursor to a cycling agent used in a cycling detection system. The amount of cycling agent is continually increased permitting amplification. The prefered system converts NADP to NAD using the conjugate label and the cycling system interconverts NAD and NADH.

Abstract: The present invention provides a method for determining a ligand or receptor which comprises carrying out an assay for the ligand or receptor, the assay requiring a labelled component, wherein the labelled component is a conjugate between a ligand or a receptor and a primary enzyme that is itself capable of producing or removing a modulator for a secondary system or that is the first enzyme in an enzyme system that is capable of producing or removing a modulator for a secondary system, and determining that portion of labelled component to be determined by allowing the primary enzyme and any other enzymes in the enzyme system, to produce or remove the modulator for the secondary system, allowing the secondary system to function in the presence or absence as appropriate of the modulator, and determining a product of the secondary system.

Abstract: An immunoassay is disclosed where the label is an enzyme which converts a precursor into a cycling factor which in turn is interconverted in a cycling detection system. The detection system is amplified by the enzyme label constantly increasing the amount of cycling factors in the system. The system of NADP to NAD with NAD cycling to NADH and back is preferred.