Periodic Acid Leucofushin Method (PAS)

Created by Kathleen Patrick, Modified on Fri, 8 Nov at 8:46 AM by Kathleen Patrick

EMS26853

Components:

Schiff’s Reagent

Periodic Acid 1%, Aqueous

Sodium Bisulphite 0.05M Aqueous

Mayer’s Acid Hemalum Solution

Weigert's Iron Haematoxylin A

Weigert's Iron Haematoxylin B

Picric Acid, Saturated Aqueous

Orange G Solution, 1%

Fixation:

Zenker Fluid or 10% Formalin

Sections:

Paraffin @ 6µm

Staining Procedures:

Deparaffinise and hydrate to distilled water.
Rinse in tap water. Oxidize in Periodic Acid 1% Aqueous for ten minutes. Wash five minutes in running water.
Stain ten minutes with Schiff’s Reagent
Pass directly to three successive baths of two minutes each in Sodium Bisulfite 0.05M. Wash in running tap water for ten minutes.
Stain in Weigert’s Hematoxylin or Mayer’s Acid Hemalum for two to five minutes, wash in tap water.
To prepare Weigert’s Hematoxylin:
Mix equal parts of Weigert’s A and Weigert’s B just before use.
Counterstain for one minute woth Picric Acid, Saturated (Aq) or Orange G, 1%. (A gram-Weigert staining procedure may be substituted for steps 6-8).
Dehydrate in two changes each of 95% and absolute alcohol. Clear through Alcohol-Xylene and two changes of Xylene
Mount in Clarita.

Stain Results:

Nuclei	Black on Blue
Collagen	Pink (Orange if Picric Acid is used as counterstain)
Reticulm	Purplish Red (Orange-red if Picric Acid is used)
Glycogen-	Dark Purplish Red
Epithelial Mucin	Red-Purple to Violet
Filbrin	Pink (Pink to Violet if the Weigert Fibrin Variant was used as a counterstain)
Cytoplasm	Gray, yellow or Orange (depending on the counterstain)

References:

Clark, G: Staining Procedures, Williams & Wilkins. Co., Baltimore, 3rd Ed. C.1973, P. 156.