What is the procedure for acid-fast staining?
Procedure of Acid-Fast Stain
- Prepare bacterial smear on clean and grease free slide, using sterile technique.
- Allow smear to air dry and then heat fix.
- Cover the smear with carbol fuchsin stain.
- Heat the stain until vapour just begins to rise (i.e. about 60 C).
- Wash off the stain with clean water.
What are the 3 main steps of an acid-fast stain?
Acid-Fast Staining Instructions
- Air dry and heat fix a thin film of microorganisms.
- Flood the slide with Carbolfuchsin.
- Flood slide with Acid Alcohol for 30 seconds.
- Counterstain by flooding the slide with Methylene Blue for 30 seconds.
- Dry the slide by putting it between the pages of a book of Bibulous paper.
What is the most critical step in acid-fast stain?
What is the most important step of the Acid-Fast procedure? The decolorizer step is the most important part of the Acid-Fast stain procedure!
Why is methylene blue used in acid-fast staining?
After the auramine dye has fully stained the smear, a drop of acid alcohol is applied for one to two minutes to decolorize the smear. Methylene blue or potassium permanganate is used as a counterstain to provide background color.
Which of the following reagent are parts of the acid-fast stain procedure?
Reagents used in the procedure include Ziehl–Neelsen carbol-fuchsin solution, 1% acid alcohol, and methylene blue solution [15].
What are AFB?
Acid-fast bacillus (AFB) is a type of bacteria that causes tuberculosis and certain other infections. Tuberculosis, commonly known as TB, is a serious bacterial infection that mainly affects the lungs. It can also affect other parts of the body, including the brain, spine, and kidneys.
What is the purpose of acid-fast stain?
Acid fast stains are used to differentiate acid fast organisms such mycobacteria. Acid fast bacteria have a high content of mycolic acids in their cell walls. Acid fast bacteria will be red, while nonacid fast bacteria will stain blue/green with the counterstain with the Kinyoun stain.
Why is heat necessary in acid-fast stain?
During the acid fast stain, heat is used as a mordant to allow the primary stain to penetrate the waxy mycolic acid layer. The heat will prevent the cells from being destained using acid-alcohol. Because these cells hold fast to the primary stain with acid alcohol treatment, they are termed acid fast positive.
What dyes are used in acid-fast staining?
A. The dyes used in the acid-fast staining technique include carbol fuchsin (primary dye), acid alcohol (decolourizer), and methylene blue as a counterstain.
Why is carbol fuchsin used?
Carbol fuchsin is used as the primary stain dye to detect acid-fast bacteria because it is more soluble in the cells’ wall lipids than in the acid alcohol.
What color is acid-fast?
red
Acid fast bacteria will be red, while nonacid fast bacteria will stain blue/green with the counterstain with the Kinyoun stain.
What acid is used in acid-fast staining?
carbolfuchsin
The primary stain used in acid-fast staining, carbolfuchsin, is lipid-soluble and contains phenol, which helps the stain penetrate the cell wall. This is further assisted by the addition of heat.
What color is acid-fast stain?
Acid Fast Strain Acid fast stains are used to differentiate acid fast organisms such mycobacteria. Acid fast bacteria have a high content of mycolic acids in their cell walls. Acid fast bacteria will be red, while nonacid fast bacteria will stain blue/green with the counterstain with the Kinyoun stain.
Which bacteria are acid-fast?
Acid-fast bacteria, also known as acid-fast bacilli or simply AFB, are a group of bacteria sharing the characteristic of acid fastness….These include:
- Bacterial endospores.
- Head of sperm.
- Cryptosporidium parvum.
- Isospora belli.
- Cyclospora cayetanensis.
- Taenia saginata eggs.
- Hydatid cysts.
- Sarcocystis.
Who introduced acid-fast staining?
Paul Ehrlich
Ziehl–Neelsen staining is a type of acid-fast stain, first introduced by Paul Ehrlich. Ziehl–Neelsen staining is a bacteriological stain used to identify acid-fast organisms, mainly Mycobacteria.
Why is steam used in acid-fast staining?
Steam helps to loosen up the waxy layer and promotes entry of the primary stain inside the cell. The smear is then rinsed with a very strong decolorizer, which strips the stain from all non-acid-fast cells but does not permeate the cell wall of acid-fast organisms.
What are cold methods of acid-fast staining?
The Kinyoun method or Kinyoun stain (cold method), developed by Joseph J. Kinyoun, is a procedure used to stain acid-fast species of the bacterial genus Mycobacterium. It is a variation of a method developed by Robert Koch in 1882.
What Colour is Safranin?
basic red 2
Safranin (also Safranin O or basic red 2) is a biological stain used in histology and cytology. Safranin is used as a counterstain in some staining protocols, colouring cell nuclei red.
What are the steps in acid fast staining?
– First, cover the smear on the slide with Carbol fuchsin and start heating until steam rises. Allow the smear + stain for 5 minutes. – Cover the slide with 20% Sulphuric acid (H 2 SO 4 ). The red color of the smear change into a yellowish-brown. – Wash the slide. Repeat step 2. – Counterstain with methylene blue for 20 to 25 seconds.
What are the cold methods of acid fast staining?
Prepare and fix the specimen smear prior to staining.
How is acid fast staining used diagnostically?
The acid-fast stain is a differential stain used to identify acid-fast organisms such as members of the genus Mycobacterium. Acid-fast organisms are characterized by wax-like, nearly impermeable cell walls; they contain mycolic acid and large amounts of fatty acids, waxes, and complex lipids.
Why is acid fast staining necessary?
– Requirement. A clean grease free slide. – Procedure. Take a clean grease free slide and prepare a smear using nichrome wire loop. – Flowchart of the Acid Fast staining procedure – Functions of reagents used in acid-fast staining technique. It is a primary stain. – 2. Acid alcohol. – 3. – Mechanism. – Observation. – Some important points.