We describe a rapid method whereby isolated chloroplasts from Euglena gracilis can be separated in a Ficoll gradient according to their surface pK's by isoelectric focusing in one hour or less. The linear Ficoll gradient is made isotonic over the whole separation distance by addition of sucrose. No released proteins of the isolated chloroplasts are detectable after isoelectric focusing. Modifications of the chloroplast envelope during the cell cycle of Euglena gracilis are evident by alterations of their isoelectric points.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.