In order to enrich populations of homogeneous cellular types we
dissociated gastric mucosa by enzymatic techniques. In addition, we used SEM
to monitor the progressive etching of the mucosa. Two enzymes were tested:
collagenase III with minimum proteolytic activity and Pronase with broader
proteolytic effects. The gastric mucosa was exposed to the effect of the
enzymes using everted stomach preparations. In this way the digestive action
occured progressively from the lumen of the stomach toward the base of the
glands. This “etching” process could be monitored conveniently by SEM. After
incubation for periods varying from 30 to 210 minutes the tissues were
stretched on dental wax, fixed in 2 % glutaralheyde, post-fixed in osmium,
dehydrated, critical point dryed and coated with gold. A model MSM-5
“Mini-SEM” was used for observation. Gentle uncurling of the preparation
before coating with gold produced fractures which revealed the structure of
the gastric glandsin more detail.