1. Alcianblue –PAS (Periodic-Acid-Schiff)
- for simultaneous display of neutral and acid mucosubstances

2. Stain: Alcian Blue
water-soluble phthalocyanine stain - (pH 2.5) - undifferentiated detection of acid mucosubstances, without distinction of carboxyl- and sulfate groups
here: (pH 1.0) – inhibition of dissociation of carboxyl groups - differentiation between carboxyl and sulfate groups

3. Stain: PAS (Periodic Acid Schiff reaction)
- Oxidation of hydroxyl group of polysaccharides with periodic acid to aldehyde groups, reaction also with equivalent structures (amino- or alklyamino groups instead of OH-groups)
reaction with Schiff reagent – staining of the aldehyde groups
PAS reaction include polysaccharides, neutral mucopolysaccharides, muco- and glycoproteins, glycolipids, unsaturated lipids and phospholipids

4. Method:
Fixation: Formalin

5. Result: Alcian Blue and PAS reaction on standard tissue
nuclei - blue
acid glycosaminoglycan – pale pink
acid mucopolysaccharides – bright blue
mineralized hard tissue – pale red
glycogen and glycoproteins – dark purple
neutral mucopolysaccharides – purple
Alcian Blue and PAS reaction on sponge tissue
- Alcian Blue staining doesn´t work – no bright blue substances (saccharides), or no acid mucosubstances; Time to short (> 5 min)
nuclei - blue - glycoproteins? – dark purple

6. Result:
Spongin
Glycoproteins?
Nuclei