Microbiology

What does carbol fuchsin stain do?

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. … Carbol-fuchsin is also used as a topical antiseptic and antifungal. Its CAS number is 4197-24-4. It is also known as “Castellani’s paint” in the US.

Why is carbol fuchsin used in acid fast stain?

The primary stain used in acid-fast staining, carbol fuchsin, is lipid-soluble and contains phenol, which helps the stain penetrate the cell wall. … 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 is the composition of carbol fuchsin?

Magenta II is a hydrochloride that is the monohydrochloride of 4-[(4-aminophenyl)(4-iminocyclohexa-2,5-dien-1-ylidene)methyl]-2-methylaniline. One of the minor constituents of Basic fuchsin, together with pararosanilin, rosanilin and new fuchsin. It has a role as a histological dye and a fluorochrome.

Is Safranin the same as carbol fuchsin?

Bacteria that retain the initial crystal violet stain (purple) are said to be “gram-positive,” whereas those that are decolorized and stain red with carbol fuchsin (or safranin) are said to be “gram-negative.” This staining response is based on the chemical and structural makeup of the cell walls of both varieties of …

What does Ziehl-Neelsen stain?

Ziehl-Neelsen stain is a staining method to highlight Acid-Alcoholic Resistant Bacilli (AARB). This group of bacilli includes: Mycobacterium tuberculosis, Mycobacterium leprae and other mycobacteria.

What does an Endospore stain tell you?

Endospore staining is a technique used in bacteriology to identify the presence of endospores in a bacterial sample. Within bacteria, endospores are protective structures used to survive extreme conditions, including high temperatures making them highly resistant to chemicals.

What color is carbol fuchsin dye?

Application of Reagent Cell colour
Acid fast
Primary dye Carbol fuchsin Red
Decolorizer Acid alcohol Red
Counter stain Methylene blue Red

Is carbol fuchsin acidic or basic?

Carbol Fuchsin is a basic dye which forms a yellow-brown compound in presence of acid. It is mainly required for the staining of mycobacteria. The waxy walls of mycobacteria helps in retaining the dye within cells.

How is carbol fuchsin different than most biological stains used in the microbiology laboratory?

The stained smears are washed with an acid-alcohol mixture that easily decolorizes most bacteria except acid-fast microbes. … Therefore, carbolfuchsin has a higher affinity for lipids than for acid-alcohol and will remain with the cell wall when washed with acid-alcohol.

How do you make Ziehl Neelsen stain?

  1. Step 2: Smear Preparation (Review) …
  2. Cover the smear with carbolfuchsin dye. …
  3. Dry heat for 2 minutes.
  4. Cool and rinse with water. …
  5. Wash the top and bottom of slide with water and clean the slide bottom well.
  6. Counterstain with Methylene Blue for 30 seconds to 1 minute.

What is dilute carbol fuchsin?

Category: Gram Stains – Concentrated x10. For use in the Gram’s Staining method for the initial differentiation of Gram Positive and Gram Negative bacteria. Product Code: PL.8004.

Which stain is present in ZNCF stain?

ZNCF Staining Kit is supplied by Micromaster. This kit contains a 125ml bottle of each, Carbol Fuschin, Acid Fast Decolourizer and Methylene Blue (Loefflers).

What is safranin Class 9?

Safranin is a certified stain for chromosomes. … It can be used to stain animals as well as plant cells for better cytological and histological analysis.

Is carbol fuchsin a mordant?

These non-acid fast cells are counterstained with methylene blue. The method you will be using for your acid fast stain, the Ziehl-Neelsen method, uses carbolfuchsin mixed with phenol as a mordant. The waxy mycolic acid of acid fast bacteria is quite sticky and makes preparing a thin smear difficult.

Why is Gram’s iodine added to the slide?

Briefly rinse the slide with water. The heat-fixed cells should look purple at this stage. Add iodine (Gram’s iodine) solution (1% iodine, 2% potassium iodide in water) for 1 minute. This acts as a mordant and fixes the dye, making it more difficult to decolorize and reducing some of the variability of the test.

Why is Ziehl-Neelsen method called hot method?

The Ziehl-Neelsen method of staining is also called the hot method as it involves heating the carbolfuchsin stain. In contrast, the historic method of staining called the Kinyoun method does not involve heating and is hence known as the cold method.

How is Ziehl-Neelsen method different to Kinyoun method?

The fundamental difference between the two carbolfuchsin-based methods is whether heat is used during the primary staining process. The Ziehl-Neelsen method uses heat to infuse the carbolfuchsin into the acid-fast cells, whereas the Kinyoun method does not use heat.

What are the 3 objectives of the endospore stain?

The main purpose of endospore staining is to differentiate bacterial spores from other vegetative cells and to differentiate spore formers from non-spore formers.

What is the function of endospore?

It allows the bacterium to produce a dormant and highly resistant cell to preserve the cell’s genetic material in times of extreme stress. Endospores can survive environmental assaults that would normally kill the bacterium.

What are the reagents used in the endospore stain?

Endospore staining techniques are classified based on the types of reagents used; Schaeffer Fulton Stain- used Malachite Green dye and safranin. Dorner method of endospore staining –uses Carbolfuchsin stain, acid alcohol, and Nigrosin solution)

What is ZN stain for AFB?

Page: 1 of 3. ACID-FAST BACTERIA – ZIEHL-NEELSEN STAIN (AFB) PURPOSE: Used in the demonstration of acid-fast bacteria belonging to the genus ‘mycobacterium’, which include the causative agent for tuberculosis.

How do you stain sputum for AFB?

  1. The tissues are smeared on the slides. …
  2. Then smear from sputum is fixed by heat or alcohol. …
  3. Flood the slide with carbol fuchsin stain. …
  4. Wash slides thoroughly with water.
  5. Decolorize with acid-alcohol (5 min). …
  6. Flood slide with methylene blue counterstain for 1 min.

What is flagella stain?

The flagella stain allows observation of bacterial flagella under the light microscope. Bacterial flagella are normally too thin to be seen under such conditions. The flagella stains employs a mordant to coat the flagella with stain until they are thick enough to be seen. … Flagella can vary by number and location.

How do you make carbol fuchsin solution?

Preparation of reagents. Carbol fuchsin (1%) was prepared from 10 g of basic fuchsin (Hi-Media) dissolved in 100 ml of methanol (Qualigens) and 50 ml of melted phenol (Qualigens) in a flask maintained at 60°C in a water bath. This solution was made up to 1,000 ml with distilled water.

What is the principle of AFB staining?

The mycobacterial cell wall contains mycolic acids, which are fatty acids that contribute to the characteristic of “acid-fastness.” The principle of the AFB smear is based on the fact that mycolic acid in the cell wall of AFB render them resistant to decolorization with acid alcohol.

How long do you flood the slide with carbol fuchsin in an acid-fast stain?

Flood the slide with Carbol Fuchsin Counterstain (Methylene Blue) and allow the slides to stain for 30 to 45 seconds.

Why is acid alcohol used as a decolorizing agent?

Acid alcohol is used as a decolorizing agent because of its interaction with the bacterial cell wall.

How do you dilute strong carbol fuchsin?

  1. Dilute carbol fuchsin : 10ml of strong carbol fuchsin diluted with 90ml distilled water . …
  2. Staphylococcus aureus Streptococcus spp Clostridium spp Neisseria spp Escherichia coli Haemophilus spp.

What are the Gram stain reagents?

Reagents needed for Gram staining include: Crystal violet (primary stain) [1] Gram’s iodine solution (the mordant) [1] Acetone/ethanol (50:50 v:v) (the decolorizer) [1] 0.1% basic fuchsin solution (the counterstain) [1]

What color is Nigrosin?

Nigrosin, an aqueous blue-black acid dye of the azine series, in conjunction with Biebrich scarlet, orange G and formic acid as mordant, it is found an excellent triple panchromatic rapid stain for histological purposes.

How do you stain TB?

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 a smear in microbiology?

A bacterial smear is simply that—a small amount of culture spread in a very thin film on the surface of the slide. To prevent the bacteria from washing away during the staining steps, the smear may be chemically or physically “fixed” to the surface of the slide.

What is the Formulae of lacto Aceto Carmine?

Acetocarmine preparation (1% solution) Carmine is a basic dye that is prepared from the insect Coccus cacti. Dissolve 10 g carmine (Fisher C579-25) in 1 L of 45% glacial acetic acid, add boileezers, and reflux for 24 h. Filter into dark bottles and store at 4°C. This solution can be stored for a long time.

What is a cationic stain?

Basic stain (Cationic stain) Chromogen or coloured part of basic stain is positively charged. so, it is also known as cationic stain. Basic stain are used to stain negatively charged components such as bacterial cell.

Why is safranin used?

Safranin is used as a counterstain in some staining protocols, colouring cell nuclei red. This is the classic counterstain in both Gram stains and endospore staining. It can also be used for the detection of cartilage, mucin and mast cell granules.

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