Separation and Ultrastructure of Proplastids from Dark-grown <i>Euglena</i> Cells

Abstract

A procedure for the separation of proplastids free of mitochondria from dark-grown Euglena cells has been developed. A fraction enriched in proplastids was used for freeze-etching study of proplastid structure. The prolamellar body in freeze-etched replicas appeared sponge-like, with thylakoids, often vesicular, emerging from it. The prolamellar body and the thylakoids were covered by particles of about 100A in diameter. No larger particles, typical of light-grown chloroplasts, were observed.