This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Web of Science (23) Citing Articles via Google Scholar Google Scholar Articles by Salisbury, J. L. Articles by Floyd, G. L. Search for Related Content PubMed PubMed Citation Articles by Salisbury, J. L. Articles by Floyd, G. L. Agricola Articles by Salisbury, J. L. Articles by Floyd, G. L.

Articles

Isolation of Intact Chloroplasts of Euglena gracilis by Isopycnic Sedimentation in Gradients of Silica ^1,2

^a Department of Botany and the Particle Separation Facility, Rutgers University, New Brunswick, New Jersey 08903

A technique is described for the isolation of structurally intact and partially active chloroplasts from photoheterotrophically grown Euglena gracilis. The separation of intact chloroplasts from stripped chloroplast membranes and other subcellular particles was achieved by sedimentation in continuous, isosmotic density gradients of Ludox AM, a silica sol.

The final preparations contained an average of 93% intact chloroplasts and corresponded to approximately 10% of the the chlorophyll of the original cell suspension and 20 to 30% of the chlorophyll layered on the gradients.

The chloroplasts obtained were intact by the criteria of ultrastructure, their content of ribulose diphosphate carboxylase, and their activity in a modified Hill reaction assay (U. Heber and K. A. Santarius. 1970. Z. Naturforsch. 25b: 718-727). In addition, the isolated chloroplasts were capable of incorporating amino acids into protein in the light.

¹ This work was supported in part by grants from the United States Public Health Service (HD-05602) to C. A. Price, the Rutgers Research Council, and the Charles and Johana Busch Memorial Fund to A. C. V. and G. L. F. Journal paper of the New Jersey Agricultural Experimental Station.

² Part of a thesis (J. L. S.) submitted in partial fulfillment of the requirements for the degree of Master of Science, Department of Botany, Rutgers University, New Brunswick, N. J. 08903.