What is the role of tannic acid in flagella staining procedures?

What is the role of tannic acid in flagella staining procedures?

Bacterial flagella are appendages used for motility. Since flagella are too thin to be seen by compound light microscopy, staining methods employ the use of a mordant (often tannic acid) to make them thick enough to see using an oil immersion objective.

How do you stain bacterial flagella?

Apply 2 drops of RYU flagella stain gently on the edge of the cover slip. The stain will flow by capillary action and mix with the cell suspension. After 5 to 10 minutes at room temperature, examine the cells for flagella. Cells with flagella may be observed at 100x.

What is the principle of the flagella stain?

The basic point about the flagella stain is that the combination of chemicals produces a thickened coat around the flagella, making them more easily seen with a light microscope. Flagella are extremely thin and of small diameter, so they are below the resolution of the light microscope if unstained.

What kind of stain is a 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.

What is often used for flagella staining?

Flagella staining thickens the flagella by first applying mordant (generally tannic acid, but sometimes potassium alum), which coats the flagella; then the specimen is stained with pararosaniline (most commonly) or basic fuchsin (Figure 8).

Why is mordant necessary for the staining of bacterial flagella?

Principle: Because bacterial flagella are very thin and fragile a special stain (flagella stain) is prepared that contains a mordant. This mordant allows piling of the stain on the flagella, increasing the thickness until they become visible. Various arrangements of flagella are seen on different cells.

Why are flagella so difficult to stain?

Flagella are very thin, so they don’t retain munch stain, making them very difficult to see without using special techniques.

Can you see flagella in a Gram stain?

Principle of Flagella Stain Flagella are too thin to be visualized using a bright field microscope with ordinary stains, such as the Gram stain, or a simple stain.

What is the principle behind acid fast staining?

Principle of Acid-Fast Stain When the smear is stained with carbol fuchsin, it solubilizes the lipoidal material present in the Mycobacterial cell wall but by the application of heat, carbol fuchsin further penetrates through lipoidal wall and enters into cytoplasm. Then after all cell appears red.

What is positive and negative staining?

Alternatively, positive and negative staining techniques can be combined to visualize capsules: The positive stain colors the body of the cell, and the negative stain colors the background but not the capsule, leaving halo around each cell.

What is used for staining spores and flagella?

Acid-fast bacteria are red; non-acid-fast cells are blue. Uses heat to stain endospores with malachite green (Schaeffer-Fulton procedure), then cell is washed and counterstained with safranin. Used to view and study flagella in bacteria that have them.

Why is mordant used in the Gram stain in the flagella stain?

How are flagella stained using Leifson staining method?

Since flagella are too thin to be seen by compound light microscopy, staining methods employ the use of a mordant (often tannic acid) to make them thick enough to see using an oil immersion objective. Two protocols are described. Basic Protocol 1 is a modified Leifson method and is the one that many microbiologists have adapted.

Why is Leifson’s stain made up of tannic acid?

The Leifson’s stain is made up of tannic acid ,basic fuschin stain prepared in alcohol base. When we treat Leifson’s stain with cell the tannic acid get attach to the flagella and alcohol get evaporated. After evaporation of alcohol the thickness of flagella is increased due to deposition of tannic acid.

What kind of mordant is used to stain flagella?

Since flagella are too thin to be seen by compound light microscopy, staining methods employ the use of a mordant (often tannic acid) to make them thick enough … Differential staining of bacteria: flagella stain

How are flagellar stains different from other bacterial stains?

Staining bacterial flagella differs from staining other bacterial structures because it usually requires extraordinary care for the slides, stain, and cells. Flagellar stains are painstakingly prepared to coat the surface of the flagella with dye or a metal such as silver.