Purification of biological conjugates by size exclusion chromatography

A method for separating a biological conjugate from an aggregate in a mixture produced by manufacturing the biological conjugate, the method comprising the steps of:

• (a) providing a mixture comprising the biological conjugate and the aggregate, wherein the mixture comprises a batch size ranging from about 50 to about 150 mg and the biological conjugate comprises a chemiluminescent label covalently linked to an anti-biotin antibody;
• (b) providing a chromatography column containing a gel, wherein the gel comprises at least one polysaccharide;
• (c) introducing the mixture of step (a) into the chromatography column;
• and
• (d) recovering the biological conjugate from the column;
• wherein the biological conjugate has a globular structure, the aggregate comprises aggregated protein and aggregated label, and the molecular weight of the aggregate is the same as to double the weight of a single molecule of the biological conjugate.