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The alcohol is a decolorizer. In gram negative organisms, the small amount of peptidoglycan can't hold onto the crystal violet in the presence of the alcohol and so becomes decolorized. The gram positive organisms have a much thicker peptidoglycan layer, and so the crystal violet stays in even with washing by alcohol.
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Purpose of decolorizing agent?
The decolorizer, usually acetone or alcohol, is used to wash the Crystal Violet stain from the Gram Negative cells. From this point Safranin stain is used to stain the Gram Negative cells. The final color for Gram Negative will be a Red/Pink color.
Which step of a gram stain can be omitted without affecting determination of the reaction?
you can omit the last step - the safranin counterstain
What happens if you forget to add acetone to a gram negative stain?
When performing the Gram stain, acetone is used as a wash step between the iodine and safranin. By not washing, all stains will remain crystal violet purple, and none will appear safranin red/pink.
Why is the counter stain for gram stain procedure differ from the counter stain used for acid fast procedure?
Safranin
If you used distilled water instead of alcohol in a gram staining procedure what would be the colour of gram positive and what of gram negative bacteria?
If we use distill water in gram staining instead of alcohol then both gram +ve and gram -ve will appear blue as distilled water is not able to remove crystal violet from cell wall and so when we counter stain the cell with safranin it will give no effect of that and cell show only blue colour
Purpose of decolorizing agent?
The decolorizer, usually acetone or alcohol, is used to wash the Crystal Violet stain from the Gram Negative cells. From this point Safranin stain is used to stain the Gram Negative cells. The final color for Gram Negative will be a Red/Pink color.
What is the gram stain of H5N1?
The Gram stain is used for bacteria and not for viruses.
Which step of a gram stain can be omitted without affecting determination of the reaction?
you can omit the last step - the safranin counterstain
What happens if you forget to add acetone to a gram negative stain?
When performing the Gram stain, acetone is used as a wash step between the iodine and safranin. By not washing, all stains will remain crystal violet purple, and none will appear safranin red/pink.
Why does the counterstain not change the color of all of the cells is it because the primary stain repels or masks the secondary stain?
In a gram stain the primary stain is crystal violet. Iodine then sets that dye into the gram positive cells while alcohol washes out the crystal violet from the gram negative cells. Then safranin, which is the counterstain in a gram stain, is used to dye the rest of the bacteria. This is the example I can give you of why a counterstain does not change the look in all the cells. Though safranin stains all the cells, the gram positive cells that were dyed purple from crystal violet don't look pink - only the gram negative do.
Why is the counter stain for gram stain procedure differ from the counter stain used for acid fast procedure?
Safranin
Why is decolorization necessary when performing a gram stain?
During the procedures of a gram stain, decolorization is necessary to remove any stain or color from the gram negative cells. When a dye is used to stain gram positive cells, both gram positive and gram negative cells retain color. Mordant is used to bind the original stain to gram positive cells so when decolorizer is used they retain color. After the mordant has been used a decolorizer is used to wash away colo in gram negative cells. Counterstains are used to stain gram negative cells to better visualize contrasting cells. An example of a decolorizer that works well is ethanol.
How is the Gram stain used to identify bacteria?
Half Answer: There are both Gram positive and Gram negative stains that are used to identify different types of Bacteria. They depend upon 'membrane content' - some stains highlight only the nuclear envelope.
Can a gram stain detect chlamydia?
A gram stain cannot detect chlamydia. A gram stain in men that finds gram negative diplococci is considered diagnostic for gonorrhea, but it can't be used in females, and it can't prove chlamydia. A gram stain in men can be used to rule out gonorrhea and possibly diagnose "non-gonococcal urethritis" if a male has symptoms. However, although it may seem that NGU is synonymous with chlamydia, there are other possible causes.
What are the uses of the gram stain technique scientifically speaking?
Gram stains are used to analyze bacteria and determine their characteristics. The most popular use of a gram stain is to determine the thickness of a cell wall in bacteria.
Why do you use iodine to stain a cell?
Iodine stains starch contained in cells. Iodine is also used to distinguish between Gram negative and Gram positive bacteria. The Gram stain contains iodine.
Why do you capitalize the letter G in Gram Stain?
Yes, when it is used as a title.
