Table of Contents
- 1 Does capsule stain have a Decolorizer?
- 2 What is the Decolorizer for the Endospore stain?
- 3 What is the usual Decolorizer in the Gram stain procedure?
- 4 Why is there no Decolorizer in this stain?
- 5 What is the Decolorizing chemical in the acid fast stain?
- 6 Is ethanol a Decolorizer?
- 7 Is endospore stain a differential stain?
- 8 What kind of dye is used to stain capsules?
- 9 Can a capsule be stained with a reagent?
Does capsule stain have a Decolorizer?
There is no mordant in the capsule staining procedure. A 20% copper sulfate solution serves a dual role as both the decolorizing agent and counterstain. It decolorizes the capsule by washing out the crystal violet, but will not decolorize the cell. Thus, the capsule appears as a faint blue halo around a purple cell.
What is the Decolorizer for the Endospore stain?
malachite green
Here, water is used as a decolorizer. Because malachite green binds relatively weakly, it can be washed off easily. However, it cannot be washed off easily once it is locked in the spore wall. Once they take in the dye, endospores retain the dye and will be resistant to de-staining.
What is the usual Decolorizer in the Gram stain procedure?
Decolorizers are often the mixed solvent of ethanol and acetone. This step is known as “solvent treatment.” The slide is rinsed with water in 5 seconds. To prevent excess decolorization in the gram-positive cells, stop adding decolorizer as soon as the solvent is not colored as it flows over the slide.
Which method is used for capsule staining?
Bacterial capsules are non-ionic, so neither acidic nor basic stains will adhere to their surfaces. Therefore, the best way to visualize them is to stain the background using an acidic stain and to stain the cell itself using a basic stain. We use India ink and Gram crystal violet.
What 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. Flagella can vary by number and location.
Why is there no Decolorizer in this stain?
Endospores are not for reproduction: One spore forms inside of the vegetative cell. When the spore germinates, one vegetative cell will be produced. That is why there does not need to be a decolorizer in this stain: it is based on the binding of the malachite green and the permeability of the spore vs. cell wall. .
What is the Decolorizing chemical in the acid fast stain?
Ziehl Neelsen Acid-fast stain
| ACID-FAST STAIN | Cell Color | |
|---|---|---|
| Procedure | Reagent | Nonacid-fast Bacteria |
| Primary dye | Carbolfuchsin | RED |
| Decolorizer | Acid-alcohol | COLORLESS |
| Counterstain | Methylene blue | BLUE |
Is ethanol a Decolorizer?
The decolorizer, ethyl alcohol, is the most crtitical step. Ethyl alcohol is a nonpolar solvent, and thus penetrates the cell walls of Gram negative cells more readily and removes the crystal violet-iodine complex. Apply the primary dye, crystal violet to heat-fixed smears for one minute.
What is the usual Decolorizer in the Schaeffer Fulton Endospore stain procedure?
In the Schaeffer-Fulton endospore staining method, X is the decolorizer. The endospore is X resistant to the environmental stresses than the vegetative cell.
What is capsule in capsule staining?
The main purpose of capsule stain is to distinguish capsular material from the bacterial cell. A capsule is a gelatinous outer layer secreted by bacterial cell and that surrounds and adheres to the cell wall. The capsule stain employs an acidic stain and a basic stain to detect capsule production.
Is endospore stain a differential stain?
The endospore stain is a differential stain because it differentiates spore-formers from non spore-formers. Note: Formation of an endospore. The spore stains green and the vegetative cells stain red to orange.
What kind of dye is used to stain capsules?
By counterstaining with dyes like crystal violet or methylene blue, bacterial cell wall takes up the dye. Capsules appear colourless with stained cells against dark background. Capsules are fragile and can be diminished, desiccated, distorted, or destroyed by heating.
Can a capsule be stained with a reagent?
Capsules stain very poorly with reagents used in simple staining and a capsule stain can be, depending on the method, a misnomer because the capsule may or may not be stained. Negative staining methods contrast a translucent, darker colored, background with stained cells but an unstained capsule.
What is the principle of negative capsule staining?
Principle of Capsule Staining. Capsules stain very poorly with reagents used in simple staining and a capsule stain can be, depending on the method, a misnomer because the capsule may or may not be stained. Negative staining methods contrast a translucent, darker colored, background with stained cells but an unstained capsule.
Can a positive capsule stain be obtained from India ink?
India ink is difficult to obtain nowadays; however, nigrosin is easily acquired. A positive capsule stain requires a mordant that precipitates the capsule. By counterstaining with dyes like crystal violet or methylene blue, bacterial cell wall takes up the dye. Capsules appear colourless with stained cells against dark background.