Abstract: Dipsticks and other assay devices suitable for the assay of haptens are disclosed. Also disclosed are blocking agents for use in such devices.

Abstract: The invention relates to assays in which complexes between an analyte and a binding agent specific for the analyte are detected by a reporter molecule, which is capable of binding to the binding agent when the binding agent is complexed with analyte but not when the binding agent is complexed with an analyte analogue. The invention provides a method of modifying such a binding agent in order to create a tailored site where the reporter molecule may bind to the binding agent. This provides control over the location and nature of the reporter binding site. Antibodies, including bispecific antibodies, are preferred binding agents. The invention also provides novel methods for labelling antibodies close to their antigen binding site using bi- and tri-functional reagents. Modified binding agents produced by the methods described are also provided.

Abstract: The invention provides methods for stimulating the immune system using antibodies capable of activating immune cells, such as T cells, the antibodies having reversibly inhibited antigen binding sites. Selective activation of the antigen binding sites at a site where an immune response is required (e.g. by irradiation) leads to a corresponding activation of the immune response at that site. Surprisingly good results are achieved even though the antibodies do not possess any targeting moiety which causes them to selectively accumulate at the site where immune cell activation is required.

Abstract: Dipsticks and other assay devices suitable for the assay of haptens are disclosed. Also disclosed are blocking agents for use in such devices.

Abstract: Antibodies are described which can bind to a member of a binding pair and to a macromolecule in which the capability of binding to the macromolecule is reversibly inhibited by the presence of a photocleavable moiety. Favoured antibodies are bispecific antibodies, for example against a tumour cell and against an enzyme or a killer cell in which the capability of binding to the enzyme or the killer cell is inhibited until the photocleavable moiety is removed on irradiation.

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.