One of the most critical factors for optimal ribosome purification is the quality of the cells from which the ribosomes are to be isolated. The best material is usually obtained from cells growing rapidly in a rich medium at their optimal temperature and harvested in early to mid-log phase long before growth and translation start to slow. For high yields of polysomes, preserve the polysomes by chilling the culture rapidly and adding of chloramphenicol (for prokaryotes) or cycloheximide (for eukaryotes) before harvest are required. Best conditions for polysome preparations vary from different organisms and tissues.
