Abstract: The present disclosure provides an automated method for chemical treatment of cells in a mixing chamber, wherein the automatable method comprises providing cells, providing a chemical agent for treating cells, forming a liquid mixture comprising the cells and the chemical agent, and mixing the liquid mixture by providing a back-and-forth liquid flow in the mixing chamber. An automated process for purifying macromolecules, such as plasmids, and an automated system comprising a workstation configured for purifying such macromolecules are also provided.