Abstract: A method for the removal of a substance carrying a negative charge and being present in an aqueous liquid (I). The method comprises the steps of: (i) contacting the liquid with a matrix carrying a plurality of ligands comprising a positively charged structure and a hydrophobic structure, and (ii) desorbing the substance.

Abstract: The invention relates to a method and a system, suitable for automation, for the, preferably preparative, separation of amphoteric macromolecules, e.g. proteins or peptides, wherein said method comprises the steps of: (a) subjecting said mixture of macromolecules to isoelectric focusing in liquid media; (b) collecting samples from step (a), said samples containing macromolecules separated on basis of isoelectric point, and transferring each sample to a channel (13) accommodating medium for electrophoresis, said channel (13) being part of a composite body (14); (c) subjecting said samples, contained in the channels (13) in said composite body (14), to electrophoresis; and (d) allowing electrophoresis to proceed until macromolecules are eluted from said medium for electrophoresis, and collecting fractions of the samples containing macromolecules.