Abstract: A method which uses a combination of polymeric cationic and an anionic flocculants to clarify an aqueous solution containing cells of a microorganism and parts thereof is described. The anionic flocculant is based upon a copolymer of an alpha-beta unsaturated monomer of an anhydride, a carboxylic acid or salt and an alpha-beta Unsaturated sulfonic acid or salt monomer. The polymeric cationic surfactant is preferably a quaternary ammonium or tertiary amine containing polymer produced from an alpha-beta unsaturated amino monomer. The method is particularly useful for clarifying solutions wherein a bacterium is used to produce an expressed material such as a protein, peptide, or amino acid dissolved in the solution which is to be separated from the cells or cell parts.