{HEAD ~ The fractionation} can be made according to {TAIL ~ Cohn}, but also other known methods are useful, as e.g. ammoniumsulfate precipitation, the ether method, the rivanol method, precipitation with high polymeric substances and chromatographic methods, as e.g. gel filtration, ion exchange chromatography or affinity chromatography 
according to
{ HEAD ~ The fractionation } can be made according to { TAIL ~ Cohn } , but also other known methods are useful , as e.g. ammoniumsulfate precipitation , the ether method , the rivanol method , precipitation with high polymeric substances and chromatographic methods , as e.g. gel filtration , ion exchange chromatography or affinity chromatography
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