Patent ID: 8207298

Claim:
A method for separating polyethylene glycol biopolymer conjugated molecules from unconjugated molecules comprising the steps: a) applying a mixture containing a polyethylene glycol biopolymer conjugated molecule and an unconjugated molecule to a resin having a pore size and a charge that substantially captures the unconjugated molecule with such pore size that also substantially excludes the polyethylene glycol biopolymer conjugated molecule from the resin, wherein the unconjugated molecule is substantially captured by the resin and the polyethylene glycol biopolymer conjugated molecule is substantially excluded from the resin; and b) collecting the entire filtrate as a single fraction, thereby separating a polyethylene glycol biopolymer conjugated molecule from an unconjugated molecule in the absence of gradient chromatography, and recovering the polyethylene glycol biopolymer conjugated molecule.