3.25 in. x 4 in. Lantern Slides, Original Magnification: x20,000, and This was the first study to use immuno-EM to localize secretory proteins in pancreatic acinar cells. It showed that the RER cisternae, all compartments of the Golgi and all zymogen granules contained trypsinogen. We also demonstrated that trypsinogen was much more concentrated in zymogen granules than in the earlier compartments on the secretory pathway.
3.25 in. x 4 in. Lantern Slides, Cell fractionation confirmed that newly synthesized acinar cell secretory proteins moved from the RER to the periphery of the Golgi in the lumen of a smooth-surfaced membrane bounded compartment. This paper also describes the pancreatic slice system and the pulse-chase protocol used to label newly synthesized secretory proteins with radioactive leucine. The micrograph shows smooth microsomes obtained from the top band in the photograph of sucrose density gradient., and Original Magnification: x10,000