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Can you stain a staphylococcus specimen with nigrosin?
Nigrosin is a dye made of synthetic ingredients. it is a negative stain, which is what is required to be able to stain staphylococcus.
What would the slide look like under the microscope if methylene blue is used instead of nigrosin?
The stain would stain the cells rather than the background
Is counterstain a negative stain?
Yes. Eosin and acid fuchsin are also acidic dyes like nigrosin.
How do surfactants work in stain removers?
Surfectants work in stain removers to remove the stain and not damage what the stain is on. It oxidizes the stain and lifts it out of whatever its in,
What is a negative stain?
The negative staining techniques uses a dye solution in which the chromogen is acidic and carries a negative charge. (An acidic chromogen gives up a hydrogen ion, which leaves it with a negative charge.) The negative charge on the bacterial surface repels the negatively charged chromogen, so the the cell remains unstained against a colored background.
Can you stain a staphylococcus specimen with nigrosin?
Nigrosin is a dye made of synthetic ingredients. it is a negative stain, which is what is required to be able to stain staphylococcus.
Are nigrosin and malachite green a functional analogous pair of stain?
No
Is it possible to substitute methylene blue for nigrosin in the negative stain?
no
What are the materials used in capsule stain?
For the capsule stain Congo red or a Nigrosin solution can be used. Next, Maneval's stain is used.
What would the slide look like under the microscope if methylene blue is used instead of nigrosin?
The stain would stain the cells rather than the background
Why cant methylene blue be used in place of nigrosin in negative staining?
Because negative staining requires the use of an acidic stain, which will not penetrate the cells because of the negative charge on the surface of the bacteria. As a result, the unstained cells can be easily identified against the colored background.
Describe the microscopic appearance of encapsulated streptococcus if stained with safranin?
Safranin (red) is used in gram staining and endospore staining as the secondary stain. Nigrosin is used in negative staining, staining only the background and not the bacteria. Therefore, the bacteria within the capsule would stain red from the safranin. (Like in endospore staining and negative gram staining, safranin would stain the bacteria red.) Nigrosin would stain the background of the organism just as it would in negative staining. Bacteria (within capsul): stained safranin red Capsule (outer layer of bacteria): clear Background of organism: stained dark with Nigrosin
Why does nigrosin not stain bacterial cells?
Because Nigrosin is an acidic dye--carries a negative charge--and repels against the negatively charged cell walls of most bacteria.
Is counterstain a negative stain?
Yes. Eosin and acid fuchsin are also acidic dyes like nigrosin.
Which of the following is an example of an acidic stain?
Basic dyes: Crystal violet, Methylene blue, Malachite green, Safranin. Acidic dyes: Nigrosin, Congo red
Is Nigrosin Acidic or basic?
acidic
How do surfactants work in stain removers?
Surfectants work in stain removers to remove the stain and not damage what the stain is on. It oxidizes the stain and lifts it out of whatever its in,
