SELECTIVE FLOCCULATION OF NUCLEIC-ACIDS, LIPIDS, AND COLLOIDAL PARTICLES FROM A YEAST-CELL HOMOGENATE BY POLYETHYLENEIMINE, AND ITS SCALE-UP

Nucleic acids, lipid, and colloidal particulate material can be selectively flocculated from a yeast cell homogenate by the cationic polymer polyethyleneimine (PEI). Flocculation can occur from a crude homogenate, a homogenate clarified centrifugally, or by the prior use of sodium tetraborate (borax). Flocculation from a homogenate previously clarified by the use of borax is best suited for large-scale operation. The supernatant obtained following centrifugation is effectively free of nucleic acid, lipid, and particulate material with essentially 100% soluble enzyme recovery. Enzyme specific activity increases by approximately 45% compared to a zero PEI control. © 1990.