Sedimentation studies on membrane vesicles.

Analytical centrifugation was used in order to investigate the size distribution of vesicles in various membrane preparations. Under certain conditions depending among others on the speed of rotation and the temperature, a sedimentation profile was observed that was characteristic for membraneous material. Since the membrane vesicles exhibited a discontinuous distribution of sedimentation coefficients it was concluded that membrane vesicles only occur in a few size classes.