Patent ID: 7993877

Claim:
A process for purifying a recombinant albumin solution, the process comprising— (a) subjecting a first recombinant albumin solution of pH 8.0-9.5 buffered with a buffer comprising a divalent cation at a concentration of 5-250 mM, and having a conductivity in the range of 1 to 75 mS·cm −1 , to an affinity chromatography step which is run in negative mode with respect to the albumin and which utilises an affinity matrix comprising immobilised dihydroxyboryl groups, thereby obtaining a purified albumin solution; and (b) subjecting the thus purified albumin solution from step (a) to a concentration step, a diafiltration step and a cation exchange chromatography step, wherein the diafiltration step is conducted at a pH of 2.5-6.0, wherein the cation exchange step is run in negative mode with respect to albumin and under conditions such that glycosylated albumin binds to the cation exchange material, and wherein the albumin solution which undergoes cation exchange chromatography has an albumin concentration of 10-250 g·L −1 ; (c) thereby to produce a final recombinant albumin solution having a nickel ion content of less than 100 ng per gram of albumin.