Purification of biological molecules

A continuous process for the purification of a target molecule comprising the steps of:

• a) providing a sample comprising the target molecule and one or more impurities;
• b) adding at least one precipitant to the sample and removing one or more impurities, thereby to recover a clarified sample;
• c) subjecting the clarified sample from step (b) to a bind and elute chromatography step comprising at least two separation units, thereby to obtain an eluate comprising the target molecule;
• and
• d) subjecting the eluate to flow-through purification comprising use of two or more media, one of which is activated carbon and the other(s) are selected from anion-exchange chromatography media and cation-exchange chromatography media;
• wherein at least two steps are performed concurrently for at least a portion of their duration, wherein the process comprises only one bind and elute chromatography step, and wherein the process is a continuous process,
• wherein the process comprises use of one or more surge tanks and/or one or more static mixers, wherein the flow-through purification is carried out as:
• activated carbon followed by anion-exchange chromatography media followed by cation-exchange chromatography media, and
• wherein the in-line static mixer and/or surge tank is used between anion-exchange chromatography media and cation-exchange chromatography media to change pH.