A method of synthesising a biomolecule-drug-conjugate, the method comprising: (i) contacting a biomolecule with FAbsorbent F1 P HF resin, MAbsorbent A1 P resin or MAbsorbent A2P resin or a capture resin comprising a capture moiety for the biomolecule, wherein the capture moiety is: a branched ligand scaffold of formula: wherein R 1 and R 2 are the same or different and are each optionally substituted alkyl or aryl ligands, and R 3 is a solid support optionally attached by a spacer motif; or a branched triazyl scaffold of formula: wherein Q represents the attachment point to a solid support matrix, optionally with a spacer motif and Groups A and B are phenyl or naphthyl groups substituted with one or more substituents capable of hydrogen bonding, preferably one or more of - OH, -SH or -CO 2 H; under conditions suitable to immobilise the biomolecule and therefore provide an immobilised biomolecule; wherein the biomolecule is an antibody, modified antibody or antibody fragment; (ii) optionally contacting the immobilised biomolecule with a chemical modification agent or activating agent to provide a chemically modified or activated, immobilised biomolecule; (iii) contacting the immobilised biomolecule or the chemically modified or activated, immobilised biomolecule with a drug component to form an immobilised biomolecule-drug-conjugate; (iv) releasing the biomolecule-drug-conjugate from the capture resin. (i) contacting a biomolecule with FAbsorbent F1 P HF resin, MAbsorbent A1 P resin or MAbsorbent A2P resin or a capture resin comprising a capture moiety for the biomolecule, wherein the capture moiety is: a branched ligand scaffold of formula: wherein R 1 and R 2 are the same or different and are each optionally substituted alkyl or aryl ligands, and R 3 is a solid support optionally attached by a spacer motif; or a branched triazyl scaffold of formula: wherein Q represents the attachment point to a solid support matrix, optionally with a spacer motif and Groups A and B are phenyl or naphthyl groups substituted with one or more substituents capable of hydrogen bonding, preferably one or more of - OH, -SH or -CO 2 H; under conditions suitable to immobilise the biomolecule and therefore provide an immobilised biomolecule; wherein the biomolecule is an antibody, modified antibody or antibody fragment; a branched ligand scaffold of formula: wherein R 1 and R 2 are the same or different and are each optionally substituted alkyl or aryl ligands, and R 3 is a solid support optionally attached by a spacer motif; or a branched triazyl scaffold of formula: wherein Q represents the attachment point to a solid support matrix, optionally with a spacer motif and Groups A and B are phenyl or naphthyl groups substituted with one or more substituents capable of hydrogen bonding, preferably one or more of - OH, -SH or -CO 2 H; (ii) optionally contacting the immobilised biomolecule with a chemical modification agent or activating agent to provide a chemically modified or activated, immobilised biomolecule; (iii) contacting the immobilised biomolecule or the chemically modified or activated, immobilised biomolecule with a drug component to form an immobilised biomolecule-drug-conjugate; (iv) releasing the biomolecule-drug-conjugate from the capture resin.