Table I.

Giantin and GM130 in COPI Vesicles

		Content of COPI Vesicles
		Amount (Percent of starting RLG)		Average density (Percent of starting RLG)
Giantin		26 ± 1.4		108 ± 5.8
GM130		8.5 ± 1.8		35 ± 7.5

COPI vesicles isolated as described in the legend to Fig. 2 were analyzed by Western blotting for their content of giantin and GM130 compared with starting Golgi membranes. Phospholipid analysis showed that 24% of starting Golgi membrane was present in COPI vesicles (Sönnichsen et al., 1996), which permitted calculation of the average density of GM130 and giantin in the vesicles compared with starting membranes (set to 100%).