Abstract: The method of making the clear cell lysate containing plasmid DNA from a biomass obtained in a cell culture process includes filtering the biomass obtained in the cell culture process with a filter medium in the presence of diatomaceous earth acting as a filtering agent to form a filter cake containing the biomass and the filter medium, then thermally digesting the biomass in the filter cake to form a cell lysate containing the plasmid DNA and filtering the cell lysate to form a clear filtrate. The clear filtrate contains the plasmid DNA and has a clarity characterized by an OD600 of at maximum 0.05 U/cm.

Abstract: The method of separating reversibly thermally precipitable oligomeric N-substituted (meth)acrylamides and conjugates thereof from aqueous solution includes thermally precipitating the oligomeric N-substituted (meth)acrylamides and the conjugates thereof from an aqueous solution in the presence of at least one salt and then filtering in the presence of at least one filter aid. The filter aid has a wet density of 0.2–0.3 g/cc and comprises?99% cellulose with fiber lengths<75 ?m (99%) and=?m (65%). The salt can be a potassium, sodium, ammonium, calcium and/or magnesium chloride, acetate and/or sulfate salt and can be present in the aqueous solution in a concentration between 0.01 M and 3 M.