Mucicarmine staining technique is one of the oldest staining technique used for the diagnosis of mucins in histological sections.
However, with the development of staining techniques such as Alcian blue technique, PAS technique, colloidal iron technique, usage of this method has reduced gradually.
This method is useful for the demonstration of acid mucins.
Mucicarmine staining method is mainly specific for the diagnosis of mucins which have epithelial origin.
Moreover, they may be useful for the identification of adenocarcinomas.
Additionally, with the mucicarmine technique, fungal capsule of Cryptococcus neoformans also can be detected.
For the preparation of Southgate’s mucicarmine stock solution, 1 g of Carmine (alum lake), 1 g of Aluminum hydroxide and 100 ml of 50% ethanol are necessary.
Add 1 g of Carmine (alum lake), 1 g of Aluminum hydroxide and 100 ml of 50% ethanol to a 500 ml Pyrex flask.
Then shake them well. Next add 0.5g of anhydrous aluminum chloride.
After that place the Pyrex flask in boiling water containing bath.
Boil the solutions. Agitation should be done while boiling for 2.5-3 minutes.
Then cool the flask by keeping it in running tap water.
Filtering of the stain solution is necessary. It should be stored at 4°C.
For the preparation of Mucicarmine working solution, mix 10 ml Southgate’s mucicarmine stock solution with 90 ml of Distilled water.
Prepare Alcoholic hematoxylin by adding 1 g of Hematoxylin to 100 ml of 95% Ethanol.
For the preparation of Acidified ferric chloride stock solution, add 2.48 g of Ferric chloride (FeCl3·6H2O) to 97 ml of Distilled water.
Then add 1 ml Concentrated hydrochloric acid to it slowly.
For the preparation of Weigert’s iron hematoxylin working solution, mix 50 ml of Alcoholic hematoxylin with 50 ml of Acidified ferric chloride solution.
This solution should be mixed freshly.
For the preparation of Metanil yellow working solution, mix 0.25 g of Metanil yellow, 100 ml of Distilled water and 0.25 ml of Glacial acetic acid.
This solution should be stored in a brown bottle or a bottle completely wrapped with aluminum foil.
- First dewax the tissue sections.
- Then bring them down to the water through a series of graded alcohol solutions.
- Next stain the slide in Weigert’s iron hematoxylin working solution for about 10 minutes.
- Then rinse the sections in running tap water for 10 minutes. After that stain in mucicarmine working solution for 25-30 minutes.
- Rinse the slides in distilled water. It is better to rinse in two changes of distilled water.
- Then stain in metanil yellow working solution for 30–60 seconds.
- Rinse the stain quickly in distilled water.
- Dehydrate the tissues in graded alcohol solutions, clear in xylene and finally mount with a mounting medium.
Acidic epithelial mucins can be seen in deep rose to red colour.
Nuclei stain I black clour. Other tissue elements stain in light yellow colour.
The staining period can be adjusted accordingly.
Mainly the staining period of staining with mucicarmine working solution can be increased up to 60 minutes.