Abstract: A reagent for conjugation to a biomolecule, wherein the reagent is a single molecule with at least three functional parts and has schematic structure (I): a) wherein a trifunctional cross-linking moiety is coupled to b) an affinity ligand via a linker 1, said affinity ligand being capable of binding with another molecule having affinity for said ligand, to c) an effector agent, optionally via a linker 2, said effector agent exerting its effect on cells, tissues and/or humorous molecules in vivo or ex vivo, and to d) a biomolecule reactive moiety, optionally via a linker 3, said moiety being capable of forming a bond between the reagent and the biomolecule.

Abstract: Water-soluble discrete multi-biotin-containing compounds with at least three (3) biotin moieties are disclosed. The water-soluble biotin-containing compounds may additionally comprise one or more moieties that confer resistance to cleavage by biotinidase or that is cleavable in vitro or in vivo. The discrete multi-biotin-containing compounds may include a reactive moiety that provides a site for reaction with yet another moiety, such as a targeting, diagnostic or therapeutic functional moiety. Biotinylation reagents comprising water-soluble linker moieties are also disclosed and may additionally comprise a biotinidase protective group. Methods for amplifying the number of sites for binding biotin-binding proteins at a selected target using multi-biotin compounds also are disclosed.

Abstract: A reagent for conjugation to a biomolecule for diagnosis and treatment of human and animal conditions and diseases is described, wherein the reagent is a single molecule with at least three functional parts and has schematic structure (1), a) wherein a trifunctional cross-linking moiety is coupled to b) an affinity ligand via a linker 1, said affinity ligand being capable of binding with another molecule having affinity for said ligand to c) an effector agent, optionally via a linker 2, said effector agent exerting its effects on cells, tissues and/or humorous molecules in vivo or ex vivo, and to d) a biomolecule reactive moiety, optionally via a linker 3, said moiety being capable of forming a bond between the reagent and the biomolecule.