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counterstains are selected to be contrasting color so that the target of the primary stain can easily be differentiated on a contrasting background.
This makes life easier, when, for example you need to count the number of nuclei in a smear, or number of gram positive bacteria in a mixed population.
Wiki User
∙ 15y ago
Wiki User
∙ 14y agoA differential stain uses 2 dyes of contrasting color to help distinguish between different microbial groups or cell parts. A counterstain is used in a differential stain procedure as a contrasting dye to the primary stain.
Wiki User
∙ 13y agoA counterstain, safranin is applied, which stains the colorless gram-negative cells. the appearance of gram positive cells is unchanged because the primary stain, crystal violet, is a much more intense stain than safranin.
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What is the secondary stain in gram stain procedure?
It is crystal violet & stains all cells purple.
What color are gram negative cells?
Gram positive bacterial stain purple. They do not take up the counter stain.
What is the difference between gram plus and?
Gram positive bacteria stain purple with the Gram stain. This is because of the fact that they contain a thick layer of murein in their cell wall, which takes up the stain very well. Gram negative bacteria, however, do not display the thick layer of peptidoglycan on their outer surface. Therefore, they stain red with the counter stain.
What structure is stained in a counterstain?
Gram positive bacteria stain violet due to the presence of a thick layer of peptidoglycan in their cell walls, which retains the crystal violet these cells are stained with. If the violet can be washed out and the counter stain (pink) is added, the bacteria are Gram-.
What is the stain most useful in clinicians to decide for bacterial infection?
Methylene blue a basic stain is generally used to identify the external morphology of bacteria.The other stain which is used as differential stain and which can also differentiate the baceteia on the basis of their cell wall is gram stain i.e. Crystal voilet and is counter stained with Saffranine
Why is the counter stain for gram stain procedure differ from the counter stain used for acid fast procedure?
Safranin
What is secondary stain?
A secondary stain is Methylene blue. This type of stain is used in a acid fast staining. This type of staining test can determine medical conditions such as tuberculosis.
What is the secondary stain in gram stain procedure?
It is crystal violet & stains all cells purple.
Why add saffranin?
Saffranin is a " counter stain " . this is also a " basic dye " which is in different color than primary stain ( basic dye crystal violet ) . The purpose counter stain ( saffranin ) is to give the decolourised cells a color , that is different from first one ( crystal violet ). The microbes which are not decolourised by alcohol retains the stain, while the decolourised cell take up the counter stain ( saffranin ).
What is the counterstain in a spore stain?
the counter stain is safranin 0.5%
What color are gram negative cells?
Gram positive bacterial stain purple. They do not take up the counter stain.
What type of dye is used to stain the specimen when the acid-fast stain and the gram stain are used?
Both processes use 2 stains. The Gram staining process uses crystal violet as the primary stain and safranin as the secondary stain. Acid-fast staining uses carbol fuchsin as the primary and methylene blue as the secondary.
Why a counter stain is used in histopathological slide preparation?
The primary stain is selective - it will only highlight certain structures or proteins. The counter stain gives color and definition to the rest of the slide so that the relationship between the highlighted structure and the rest of the cell can be determined.
What happens when you only use counter stain gram positive?
poop
What is gram stain reaction for Borrelia Burgdoferi?
when stained with Gram stain Borrelia take up the counter stain which is carbol fuchsin or safranin and they appear as Gram negative spiral rods in gram film. In order to stain them the time required for staining them is little bit more as compared to normal gram staining. The initial steps are the same but once you apply the counter stain leave it for a while may be 5-10 mins depending upon the strength of counter stain. After washing the slide and drying once can see them on oil immersion lense.
Remove stain from limestone counter top?
Supposedly, a "poultice" made of hydrogen peroxide and distilled water, left to sit on the stain, will draw it out.
Do granite counter tops need any special care?
Yes, you will have to make sure your granite counter top is properly sealed or it will stain.
