The isolation of photosynthetically active chloroplasts is the starting point for many plant metabolic studies as diverse as carbon assimilation, electron flow and phosphorylation, metabolite transport, and protein targeting. Whatever the subsequent use of the chloroplasts, it is preferable to attempt to isolateintactchloroplasts, as the organelle envelope will protect the stroma and thylakoids from the deleterious effects of degradative enzymes and phenolic compounds released from leaf tissues during the preparative procedures.
