This document provides information about Periodic Acid Schiff (PAS) and Alcian Blue-Periodic Acid Schiff (AB-PAS) staining techniques. PAS staining detects glycogen and polysaccharides, staining them magenta. AB-PAS staining differentiates between acid and neutral mucins. Acid mucins stain blue with AB while neutral mucins stain magenta with PAS. The staining process for each is described in 1-2 sentences. AB-PAS staining is useful for identifying the type of mucin in samples like gastric tissue.

1. Periodic Acid Schiff
(PAS)
&
Alcian Blue- Periodic
Acid Schiff
(AB-PAS)

2. Periodic Acid Schiff (PAS)
Special stain detects glycogen
and other polysaccharides
Stain the structures containing a
high proportion of carbohydrate

3. Principle
Periodic Acid
Oxidation
Carbohydrate and
other sugars
Aldehydes
Schiff Reagent
React
Purple- Magenta colour
Aldehydes2
1

4. Applications
Glycogen storage
diseases
Paget disease of
the breast
Alveolar Soft part
sarcoma
Macrophages in
Whipple’s disease
Basement Membrane Gastric tissue to
demonstrate “Mucin”
Demonstrate “live
fungus”

5. PAS Method
Bring Section to Water
“Deparaffinization and
Rehydration”
1% Periodic Acid
5 minutes
Wash in water Treat with Schiff reagents
15 minutes
Wash in water
5 minutes
Stain the nuclei with
Hematoxylin
2 minutes
Wash in water
Dehydrate, Clear and
Mount
1 2 3 4
5 6 7 8

6. PAS Results
Mucin:
Magenta Colour
Nuclei:
Blue-Purple

7. Alcian Blue- Periodic Acid Schiff
(AB-PAS)
It’s a combination method
which utilize the properties of
both PAS and Alcian blue stains
There is two types of mucin:
1. Acid Mucin
2. Neutral Mucin
AB-PAS is used to differentiate
between the two types of mucins

8. Principle AB-PAS
Alcian Blue
Stain
Acid Mucin is
chemically blocked
PAS staining
Stain the remaining
neutral mucin Acid Mucin = Blue
Neutral Mucin = Magenta
Neutral Mucin2
1 Acid Mucin

9. Application
AB-PAS used to differentiate between acid and
neutral mucin.

10. Method
Bring Section to Water
“Deparaffinization and
Rehydration”
3% Acetic Acid
2 minutes
Stain in Alcian Blue
15 minutes in Oven!
Resine in distilled water
1 2 3 4
5
PAS
Method

11. AB- PAS Results
Acid Mucin: Blue.
Neutral Mucin: Magenta.
Mixture of above:
Purple/blue.
Nuclei: Deep blue/purple.

12. Thank you!
If any question or clarification needed contact through email