Test Catageory
فئة التحليل
Histopathology
Refrence Books
كتب مراجع
1. Bancroft’s Histopathological Techniques
Skills Required
المهارات المطلوبة
1. Histology
2. Staining
Video Resources
مصادر فيديو
Principle
1%Periodic acid will bring about oxidative cleavage of the Carbon-to-Carbon Bond in 1-2 glycol or their amino or alkyl-amino derivatives, to form Dialdehydes. Then these aldehydes will react with Schiff’s reagent to form magenta colour compound.
Solutions
1. 1%periodic acid.
2. Schiff’s reagent.
• Basic fuchsin……………..………………..stain.
• D.W……………….………………………..solvent.
• Potassium metabisulphite………..…….…. Reducing agent.
• Conc HCL.…………………………………PH.
• Activated Charcoal……………. Remove any excess Sulpher
3. Mayer’S Haematoxylin (nuclear counter stain).
• 1 g haematoxylin…………………………. stain
• 1000 ml D.W………………………………solvent
• 0.2 g sodium iodate……………………….oxidizing agent
• 50 g potassium alum……………………….mordant-
• 1 g citric acid……………………………….sharpen nuclear stain
• 50 g chloral hydrate…………………………preservative
Sample Type
The Periodic Acid-Schiff (PAS) staining technique can be used on a variety of samples. Here are some examples:
1. Glycogen: PAS staining is particularly useful for detecting glycogen deposits in the liver when glycogen storage disease is suspected1.
Mucin: Mucin, particularly acid mucin, is demonstrated by PAS. It is important in endocervical glands, intestinal glands, and bronchial glands1.
2. Fungal Samples: Certain fungi in tissue samples such as Cryptococcus neoformans, Histoplasma capsulatum, Aspergillus fumigatus, Blastomyces etc can be demonstrated by PAS stain because of high carbohydrate content in their cell wall/capsule1.
3. Tissue Samples: PAS can detect the presence of glycogen, polysaccharides, and mucin in the tissue that is either formalin-fixed, paraffin-embedded, or frozen tissue sections2.
4. Medical Renal Biopsies: PAS staining is a standard stain for medical renal biopsies3.
5. Cellulose: PAS staining is also used for staining cellulose. One example would be looking for implanted medical devices composed of nonoxidized cellulose4.
It’s important to note that the sample used depends on the specific substance you are interested in studying.
Procedure
1. Bring section to water.
2. Oxidize in 1% P.A for 5 min.
3. Wash well in different changes of D.w
4. Place in Schiff’s reagent for 15 min.
5. Wash in R.T W for (5-10) min.
6. Stain nuclei with M.H and bluing.
7. Wash in water, rinse in absolute alcohol.
8. Clear and Mount.
Results
Neutral mucin: magenta colour
Nucleus: Blue.
Notes:
1. Periodic acid is the oxidant of choice.
2. Other oxidants like potassium permanganate and chromic acid substitute Periodic acid
3. They tend to over oxidize the formaldehyde to carboxylic acid which result In a weak Schiff’s reaction.
4. Tap water after Schiff’s solution to intensify the colour of reaction.
M. Sulieman
mohammad@mlsgaate.com
1%Periodic acid will bring about oxidative cleavage of the Carbon-to-Carbon Bond in 1-2 glycol or their amino or alkyl-amino derivatives, to form Dialdehydes.
