Periodic Acid-Schiff: Counterstaining with Hematoxylin

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Periodic Acid-Schiff: Counterstaining with Hematoxylin

Hematoxylin should be used as a counterstain when the PAS is employed to demonstrate glycogen and mucins. When using a hematoxylin counterstain, continue any of the PAS staining protocols with the following steps:
ReagentTime
Harris hematoxylin with acetic acid:
2 mL acetic acid with 48 mL hematoxylin
 30 seconds
Running tap water Rinse well
In addition to the PAS reaction, the expected results:
  • Purplish-blue nuclei
Post staining procedure:
  • After counterstain, tissue sections should be rinsed well in distilled water, dehydrated with 95% alcohol, followed by 100% alcohol, cleared with xylene (or xylene substitute), and cover-slipped.

PAS with hematoxylin counterstain demonstrating basement membrane in kidney