Methods, systems and/or kits for the preparation, purification and isolation of oligonucleotide conjugates, comprising conjugation of modified antibodies or proteins with at least one modified oligonucleotide at greater than 80% efficiency to form oligonucleotide conjugates and isolating the oligonucleotide conjugates from the conjugation solution by binding the conjugates to an immobilized binder, wherein the binder may be a metal ion or an antibody.
