Isolation of immunoglobulins

A method for isolation of immunoglobulins from a solution comprising one or more immunoglobulins, said method comprising the steps of:

• (i) contacting a solution containing one or more immunoglubulins which has a pH in the range of 2.0 to 10.0 and a total salt content corresponding to an ionic strength of at most 2.0 with a solid phase matrix, comprising a functionalised matrix backbone carrying acidic ligand groups wherein the acidic ligand groups comprise a mono- or bicyclic optionally substituted aromatic or heteroaromatic moiety and an acidic group having a pKa value of less than 6, and wherein criteria (a) and (b) are fulfilled:
• (a) the solid phase matrix has a binding efficiency of at least 50% when tested at a pH in the range of 2.0 to 10.0 in the “Standard Immunoglobulin Binding Test” described herein;
• and
• (b) the stability of the solid phase matrix in 1 M NaOH is such that incubation of the matrix in 1 M NaGH in the dark at room temperature for 7 days reduces the binding efficiency at a pH in the range of one pH unit lower than the binding maximum pH value to one pH unit higher than the binding maximum pH value, as determined in the “Standard Immunoglobulin Binding Test” described herein, with less than 25% compared to a corresponding non-incubated matrix;
• whereby at least a part of the immunoglobulins becomes bound to the solid phase matrix;
• (ii) separating the solid phase matrix having immunoglobulins bound thereto from the solution;
• (iii) optionally washing the solid phase matrix;
• and
• (iv) contacting the solid phase matrix with an eluent in order to liberate one or more of the immunoglobulins from the separated solid phase matrix.