Immunoglobulin aggregates

A method for removing immunoglobulin aggregates from an immunoglobulin solution, comprising:

• i) providing a solution containing said immunoglobulin, wherein said immunoglobulin is present in said solution in monomeric and polymeric form, or
• providing a solution containing an immunoglobulin, wherein in said solution the formation of said immunoglobulin in polymeric form is induced by the application of heat,
• ii) concentrating said solution provided under i) by employing a tangential flow filtration with a constant Δp of 3.0 bar, and a constant transmembrane pressure of 0.6 bar;
• and
• iii) removing immunoglobulin aggregates from the immunoglobulin solution obtained in step ii) by filtration with a 0.2 μm pore size filter,
• whereby the number of particles in said concentrated solution of step ii) with a size of more than 1 μm is smaller than 200 times the number of particles with a size of more than 1 μm in the solution prior to the concentrating when determining the number of particles by light obscuration.