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Gram positive are purple. Just remember Positive+Purple. Gram negative are a reddish color from the safranin. After using the crystal violet, the grams iodine acts as a mordant to hold color on cell wall. When using the alcohol, the gram positive will stay purple while the gram negative will become clear. This is due to the outer cell wall of the gram negative specimen (lipopolysaccharide) basically being stripped by the alcohol, so now you have a clear specimen again. When you add the safranin it sticks to the gram negative cell wall, hince the red/pink color.
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What does gram negative on a serratia marcescens gram stain mean?
Bacteria are gram positive or gram negative. Serratia happens to be a gram negative bacteria. They appear pink on a gram stain. Gram positive bacteria stain to a purple color on a gram stain. We can classify and ID bacteria using their gram stain and shape. Some antibiotics only work on gram negative bacteria and some only work on gram positive bacteria. It helps a doctor know which antibiotic to use.
What is the different reaction of Gram-negative and Gram-positive bacteria to Gram's stain testing?
Gram-positive bacteria which take up the stain turn purple, while Gram-negative bacteria which do not take up the stain turn red.
Could a negatively charged dye stain a bacteria?
The effect on the bacteria depends if the stain is an acidic or basic stain. Most bacteria are stained when a basic stain permeates the cell wall and adheres by weak ionic bonds to the bacterial cell, which is slightly negatively charged.
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 does some bacteria stain purple and some red?
The purple stained bacteria are called gram positive bacteria and retain the stain after washing by having a thick cell wall one one layer of a heavily crossed linked material called peptidoglycan. ( Google that ) The red stained bacteria are gram negative because they posses two thinner layers of peptidogylcan cell wall that that do not hold the gram stain and it is mostly washed away in rinsing the bacterial samples.
How do you know that it is a negative or a positive bacteria?
By which type of stain colors it.
What is the advantage of the gram stain over the simple stain?
gram staining differentiates between gram negative and gram positive bacteria by showing different colors. it shows blue or purple like color for gram positive bacteria and red color for gram negative bacteria. where as simple stain gives the same color to all the types of bacteria. hence it is difficult to differentiate between them.
What is the gram stain of H5N1?
The Gram stain is used for bacteria and not for viruses.
Why is it essential that the primary stain and the counterstain be of contrasting colors?
It is essential that primary stain and the counterstain be of contrasting colors so that the target of the primary stain can easily be differentiated on a contrasting background.
Can you stain on top of the old stain?
yes you can and the stain can change colors if there is a juice stain for example thats red and a grass stain the stain color could change
What does gram negative on a serratia marcescens gram stain mean?
Bacteria are gram positive or gram negative. Serratia happens to be a gram negative bacteria. They appear pink on a gram stain. Gram positive bacteria stain to a purple color on a gram stain. We can classify and ID bacteria using their gram stain and shape. Some antibiotics only work on gram negative bacteria and some only work on gram positive bacteria. It helps a doctor know which antibiotic to use.
What is the different reaction of Gram-negative and Gram-positive bacteria to Gram's stain testing?
Gram-positive bacteria which take up the stain turn purple, while Gram-negative bacteria which do not take up the stain turn red.
Could a negatively charged dye stain a bacteria?
The effect on the bacteria depends if the stain is an acidic or basic stain. Most bacteria are stained when a basic stain permeates the cell wall and adheres by weak ionic bonds to the bacterial cell, which is slightly negatively charged.
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
Does the gram stain procedure work for all bacteria?
Yes. The gram stain procedure separates all bacteria into one of two groups - into gram-negative bacteria which do not stain purple and into gram-positive cells which do stain purple. In structural terms, the ability of a cell to become stained during the gram stain procedure is due to the chemical makeup of the cell wall.
Why is the gram stain technique more valuable than the simple stain technique in the diagnostic laboratory Under what circumstances might the simple stain be preferable to the gram stain technique?
There are two types of stains, the simple stain and the differential stain. A simple stain colors all objects the same while a differential stain is used to spot differences in microorganisms. A gram stain is a differential stain, which is used to tell the difference in gram negative and gram positive bacteria. A simple stain would stain all the organisms the same and this difference would not be noted. You would be able to determine their shape, whether it is a cocci or bacillus (rod), but not the type. I'm not sure why the simple stain would be preferable unless you just wanted a quick answer as to the shape of the bacteria. In some cases, a wet prep can be made of a presumptive gram positive cocci to tell the difference between bacteria or yeast. Otherwise, I would say that the gram stain is the only way to go.
Why does some bacteria stain purple and some red?
The purple stained bacteria are called gram positive bacteria and retain the stain after washing by having a thick cell wall one one layer of a heavily crossed linked material called peptidoglycan. ( Google that ) The red stained bacteria are gram negative because they posses two thinner layers of peptidogylcan cell wall that that do not hold the gram stain and it is mostly washed away in rinsing the bacterial samples.
