Questions and answers

What chemicals are used in acid-fast staining?

What chemicals are used in acid-fast staining?

The primary stain used in acid-fast staining, carbol fuchsin, is lipid-soluble and contains phenol, which helps the stain penetrate the cell wall. This is further assisted by the addition of heat in the form of heat (steam).

What are the two methods of acid-fast staining?

Acid-fast structures can be visualized under a microscope using two principal methods, the carbolfuchsin staining, and the fluorochrome procedure. The carbolfuchsin staining comprises of the Ziehl-Neelsen method and the Kinyoun method.

What is modified acid-fast stain?

A modified acid-fast staining method was developed for rapid detection of Mycobacterium tuberculosis and its L forms, wherein carbol fuchsin and dioxogen were mixed into the sputum smear. With this method, the dyeing time is shortened and heating is not required.

What is the Decolorizer for the acid-fast procedure?

Remel TB Decolorizer is a reagent recommended for use with the Kinyoun or Ziehl-Neelson carbolfuchsin staining procedure to differentiate acid-fast bacteria from nonacid-fast bacteria. The microscopic acid-fast staining technique is one of the earliest methods used for detection of the tubercle bacillus.

Why acid-fast bacteria Cannot be Gram stained?

Mycobacteria are “Acid Fast” They cannot be stained by the Gram stain because of their high lipid content. 2. Acid fast staining is used to stain mycobacteria. Bacteria are treated with a red dye (fuchsin) and steamed.

Who has modified acid-fast staining method?

Ziehl–Neelsen staining is a bacteriological stain used to identify acid-fast organisms, mainly Mycobacteria. It is named for two German doctors who modified the stain: the bacteriologist Franz Ziehl (1859–1926) and the pathologist Friedrich Neelsen (1854–1898).

Why do we use acid-fast staining for Mycobacterium?

This stain is used to identify Mycobacterium tuberculosis, the causative agent of tuberculosis. Acid-fast organisms have a lipoid capsule that has a high molecular weight and is waxy at room temperature. This makes the organism impenetrable by aqueous-based staining solutions.

Is Staphylococcus acid-fast?

acid fast stain. The small pink bacilli above are Mycobacterium smegmatis, an acid fast bacteria because they retain the primary dye. The darker staining cocci are Staphylococcus epidermidis , a non-acid fast bacterium.

Why is carbol Fuchsin used in acid-fast staining?

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 is the procedure for an acid fast stain?

Procedure of Acid Fast Stain. Prepare and fix the specimen smear prior to staining. Place a small strip of blotting or filter paper over the top of the specimen, and place the slide over a boiling hot water bath on a mesh surface. Cover the filter paper with the primary stain, carbolfuchsin. Leave the slide on the water bath for 3 to 5 minutes.

Why is Mycobacterium called an acid fast stain?

Acidfast Stain: Background and Introduction. Mycobacterium and many Nocardia species are called acid-fast because during an acid-fast staining procedure they retain the primary dye carbol fuchsin despite decolorization with the powerful solvent acid-alcohol.

How to make acid fast stain with carbol fuchsin?

Procedure of Acid-Fast Stain 1 Prepare bacterial smear on clean and grease free slide, using sterile technique. 2 Allow smear to air dry and then heat fix. Alcohol-fixation: This is recommended when… 3 Cover the smear with carbol fuchsin stain. 4 Heat the stain until vapour just begins to rise (i.e. about 60 )…

How are non acid fast cells stained with counterstain?

The non-acid fast organism lack the lipoidal material in their cell wall due to which they are easily decolorized, leaving the cells colorless. Then the smear is stained with counterstain, methylene blue. Only decolorized cells absorb the counter stain and take its color and appears blue while acid-fast cells retain the red color.