Table 1

Quantitation of the freeze-fracture particle density in membranes of free transport vesicles and associated cisternae of Golgi membranes incubated in vitro to reconstitute transport

Particles/μm2 in:
Free vesiclesCisternae
High particle density class (4-8 particles per probe circle)2302 ± 6542706 ± 607
Low particle density class (0-3 particles per probe circle)1074 ± 2751349 ± 328
  • Number of particles per square micrometer of membrane (plus or minus the SD) assessed with a 6-mm probe circle (see Materials and Methods). The particle density in free vesicles and that in associated cisternae were not significantly different, whereas the differences between high and low particle density classes (for both free vesicles and cisternae) were significantly different P < 0.05).