Zonal centrifugation has been used to isolate a fraction from bovine liver which appears to be derived from the Golgi apparatus . Morphologically, the fraction consists mainly of sacs and tubular elements . Spherical inclusions, probably lipoproteins, are occasionally seen in negative stains of this material . The preparation is biochemically unique . UDPgalactose : N-acetyl glucosamine, galactosyl transferase activity is concentrated about 40-fold in this fraction compared to the homogenate . Rotenone-or antimycin-insensitive DPNH-or TPNH-cytochrome c reductase activities are 60-80% of the level of activities found in microsomes . Purified organelles from bovine liver such as plasma membranes, rough microsomes, mitochondria and nuclei have negligible levels of galactosyl transferase . Some activity is present in smooth microsomes but at a level compatible with the possible presence of Golgi membranes in this fraction . The Golgi fraction does not contain appreciable amounts of enzymes such as ATPase, 5'-nucleotidase, glycosidase, glucose-6-phosphatase, acid phosphatase, or succinate-cytochrome c reductase . Similar fractions isolated from bovine epididymis also have very high levels of galactosyl transferase . The fraction is heavily osmicated when incubated for long periods of time at elevated temperatures, a characteristic property of Golgi membranes .

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The fine structure of mitochondria and submitochondrial vesicles depleted of their lipid by extraction with aqueous acetone was studied. Thin sections of mitochondrial membranes depleted of more than 95 % of their lipid retained the unit membrane structure. Densitometer tracings of the electron micrographs showed that the unit membrane of extracted mitochondria was, on the average, wider than that of unextracted controls and showed a greater variation in width. The outer membrane was lost in mitochondria from which 80-95 % of the lipids was extracted. Inner membrane particles were present on submitochondrial vesicles depleted of up to 85 % of their lipids. However, when more than 95 % of the lipid was removed, few, if any, particles remained attached to the membranes but many particles were found unattached in the background. When lipid was restored to lipid-deficient preparations, the mitochondrial membranes were found to be devoid of inner membrane particles but were fully active with respect to succinate-cytochrome c reductase activity.