The most conspicuous location of specific reaction
product was the Golgi apparatus. At low
magnifications (Fig. 4), intense deposits were
evident in some of its flattened cisternae and in all
secretory vesicles. Sometimes the contents of the
Golgi apparatus were completely obscured by
reaction product, even at higher magnifications so
that the organelle could be identified only by its
characteristic shape and location (Fig. 6). More
frequently, higher magnifications showed that the
reaction product was present on the nascent VLDL
(Fig, 8). Reaction product was often most intense
at the periphery of some of the VLDL particles
(Figs. 8 and 13). The Golgi apparatus in control
sections contained nascent VLDL whose electron
density was due only to osmium tetroxide and lead
citrate (Figs. 5, 7, and 9). Fig. 8 (top) shows
individually reacted nascent VLDL in some Golgi
cisternae whereas a few cisternae of the same Golgi
apparatus contain unreacted particles. Such partially
reacted Golgi apparatus were seen only
occasionally in livers fixed with 4% formaldehyde;