This is a combined method utilizing the properties of both the PAS and Alcian blue stain to demonstrate the full complement of tissue proteoglycans. The rationale of the technique is that by first staining all the acidic mucins with Alcian blue, those remaining acidic mucins which are also PAS positive will be chemically blocked and will not react further during the technique. Those neutral mucins which are solely PAS positive will subsequently be demonstrated in a contrasting manner. Neutral and acidic mucins, which both contain hexosamine and acidic group, are common secretions in mucous epithelium tissue.Neutral mucins major exist in gastric mucosal epidermal, pyloric gland and duodenal glands. Acidic mucins are major secreted by goblet cells in small intestine and large intestine mucosa.
1. Deparaffinize and rehydrate to distilled water.
2. Stain with Alcian blue 5-10 min. Wash quickly.
3. Treat with periodic acid for 10 min.
4. Wash well in running tap water. Wash in distilled water twice.
5. Stain with Schiff’s reagent for 15-30 min placed in dark condition.
6. Wash in running tap water for 5-10 min.
7. Dehydrate with gradient alcohol, clear in xylene and mount with resin mounting medium.
Glycogens and neutral mucins are red, acidic mucins are blue, the mixtures of acidic and neutral mucins are purple-blue. Nucleus are blue.
1.Periodic acid and Schiff’s reagent should be stored at 4℃ and storage in dark. Restore to room temperature before use and keep in dark when use. If the Shciff’s reagent turns pink, do not use.
2. Adjust staining time in Schiff’s reagent according to environmental temperature. It is recommended that reduce staining time in summer with higher temperature, while extend to 30 min in winter with low temperature.
3. If counterstain is in need, stain nucleus slightly to ensure distinguishing from blue acidic mucins easily. Friendly reminder, we also offer Hematoxylin solution, Differentiate solution and Bluing solution.