Pancreas (400X)

Why do you think is the reason the acinar epithelial cells that make up the pancreatic secretion so bright red in the apical part and so purple in the basal part?

Well, the acinar epithelial cells of the pancreas are exocrine and secrete various digestive enzymes. These are stored in vesicles apically in the cell, and are strongly stained with eosin (an acidophilic dye). The cell nucleus is located basally in these cells, and is stained purple by hematoxylin.

There are also other cells, the centroacinar cells. A centroacinar cell is the very first part of an intercalated duct and is centrally located in the acinus. Centroacinar cells (and the first parts of the insert) produce water and HCO3 ions. Only the first part of an intercalated duct is seen in this image.