Ultrastructural study of chloroplasts isolated by various fractionation methods

The chloroplasts of kohlrabi and barley leaves isolated in conventional media and examined in electron microscope showed considerable impairements of their structure. The damages were not eliminated if the centrifugation number was limited and the tonicity of the medium was reduced gradually throughout the fixation and dehydration procedure. A good yield (about 90%) of structurally intact kohlrabi chloroplasts was obtained when they were isolated from leaves pre-fixed and homogenized in medium containing glutaraldehyde.