Patent ID: 7897404

Claim:
A process for production of a fraction of conjugates, each conjugate comprising a biomolecule and a linker and having a pre-defined ratio of biomolecule to linker so that the fraction has a pre-determined and uniform stoichiometry with respect to biomolecule and linker, wherein the biomolecule has at least two reactive sites, is selected from the group consisting of polypeptides, polysaccharides, and lipopolysaccharides, and, has a molecular weight of between 5 kD and 500 kD, and wherein the linker is a hydrophilic linker having a molecular weight between 1 kD and 15 kD and containing between 4 and 60 charged residues, the process comprising: covalently coupling the biomolecule to the linker, thereby generating a mixture of coupling products comprising the conjugates having the pre-defined ratio of biomolecule to linker, fractionating by chromatography the mixture of coupling products, and collecting a fraction comprising the conjugates having the pre-defined ratio of biomolecule to linker, wherein said pre-defined ratio of biomolecule to linker is selected from the group consisting of 1:1, 1:2, 1:3, and 1:4.