For the removal of high molecular weight compounds from recombinantly produced polypeptides generally chromatographic methods are employed. It has been found that underivatized controlled pore glass (uCPG) selectively binds high molecular weight compounds present in a solution. The purified polypeptide can be recovered e.g. from the flow through of a chromatography column containing uCPG as chromatography material. It has been found that this effect is pronounced at a pH value of about 4 to 6 in buffered solutions. With approximately 100 m2 to 150 m2 uCPG surface per g of polypeptide almost 80% to 95% of the high molecular weight compounds are removed with a yield of 80% to 90% of polypeptide.