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the Gram reaction is based on the structure of the bacterial cell wall.
In Gram-positive bacteria, the dark purple crystal violet stain is retained by the thick layer of peptidoglycan which forms the outer layer of the cell.
In Gram-negative bacteria, the thin peptidoglycan layer in the periplasm does not retain the dark stain, and the pink safranin counter stain stains the peptidoglycan layer. In other word,the gram reaction refers to how the cells reacts to the gram-staining process.
What else can I help you with?
What might cause a Gram variable reaction?
A Gram-variable reaction may occur when the bacteria have an atypical cell wall structure, making it difficult to predict whether they will appear as Gram-positive or Gram-negative under a microscope. This variability in staining can be caused by factors such as age of the culture, cell wall composition, or bacterial species.
What are the gram reaction of mycobacterium?
Mycobacteria are typically Gram-positive, but their cell wall structure is unique and contains high lipid content, making them resistant to Gram staining. They are best visualized using acid-fast staining methods, such as the Ziehl-Neelsen or Kinyoun stains.
If your organisms were all blue with pink spots what is the Gram reaction if your organisms were all pink but had some blue spots what is the Gram reaction?
Gram positive cells take up the crystal violet, which is then fixed in the cell with the iodine mordant. This forms a crystal-violet iodine complex which remains in the cell even after decolorizing. It is thought that this happens because the cell walls of gram positive organisms include a thick layer of protein-sugar complexes called peptidoglycans. This layer makes up 60-90% of the gram positive cell wall. Decolorizing the cell causes this thick cell wall to dehydrate and shrink, which closes the pores in the cell wall and prevents the stain from exiting the cell. At the end of the gram staining procedure, gram positive cells will be stained a purplish-blue color. Gram negative cells also take up crystal violet, and the iodine forms a crystal violet-iodine complex in the cells as it did in the gram positive cells. However, the cell walls of gram negative organisms do not retain this complex when decolorized. Peptidoglycans are present in the cell walls of gram negative organisms, but they only comprise 10-20% of the cell wall. Gram negative cells also have an outer layer which gram positive organisms do not have; this layer is made up of lipids, polysaccharides, and proteins. Exposing gram negative cells to the decolorizer dissolves the lipids in the cell walls, which allows the crystal violet-iodine complex to leach out of the cells. This allows the cells to subsequently be stained with safranin. At the end of the gram staining procedure, gram negative cells will be stained a reddish-pink color. Remember:
What is the gram reaction of Human papellomavirus?
The Gram reaction is used to classify bacteria into two broad categories, Gram positive and Gram negative. The Gram stain characteristics of a bacterium depends on its cell wall components and thickness. The viruses do not have any cell walls or other equivalent. The viruses are too small to be seen by light microscopy, only exception is the Pox virus. So the Gram stain is not appropriate for virus identification. However, if one is able to see papilloma virus through light microscope, these may appear Gram negative. Because the crystal violet dye would be removed by decolorizer, and the counterstain (safranin or carbol fuchsin) would show its color.
Do gram negative bacteria have peptidoglycan in their cell walls?
No, gram-negative bacteria do not have peptidoglycan in their cell walls.
What three types of data are obtained from the gram stain?
The three types of data obtained from a Gram stain are cell morphology (shape and size of the cells), cell arrangement (how cells are grouped together), and Gram reaction (whether cells are Gram-positive or Gram-negative based on their cell wall composition).
What might cause a Gram variable reaction?
A Gram-variable reaction may occur when the bacteria have an atypical cell wall structure, making it difficult to predict whether they will appear as Gram-positive or Gram-negative under a microscope. This variability in staining can be caused by factors such as age of the culture, cell wall composition, or bacterial species.
Is the gram reaction due to the outer membrane?
If by outer membrane you mean cell wall, then yes.
What are the gram reaction of mycobacterium?
Mycobacteria are typically Gram-positive, but their cell wall structure is unique and contains high lipid content, making them resistant to Gram staining. They are best visualized using acid-fast staining methods, such as the Ziehl-Neelsen or Kinyoun stains.
What gram reaction would you expect if you used a culture that was growing for 72 hours?
If a culture has been growing for 72 hours, it is likely that most of the bacterial cells would have undergone multiple rounds of cell division and may have varying degrees of cell wall synthesis. As a result, it would be challenging to predict a specific gram reaction without additional information or performing a Gram stain test on the culture.
Does a bacteriums gram reaction seem to be directly related to its shape?
Yes, a bacterium's gram reaction is often related to its shape. Gram-positive bacteria have a thick peptidoglycan layer that retains the crystal violet dye used in the Gram staining procedure, while gram-negative bacteria have a thinner peptidoglycan layer and an outer membrane that does not retain the dye. The shape of the bacterium can influence how well the dye penetrates and stains the cell wall, affecting the outcome of the Gram reaction.
If your organisms were all blue with pink spots what is the Gram reaction if your organisms were all pink but had some blue spots what is the Gram reaction?
Gram positive cells take up the crystal violet, which is then fixed in the cell with the iodine mordant. This forms a crystal-violet iodine complex which remains in the cell even after decolorizing. It is thought that this happens because the cell walls of gram positive organisms include a thick layer of protein-sugar complexes called peptidoglycans. This layer makes up 60-90% of the gram positive cell wall. Decolorizing the cell causes this thick cell wall to dehydrate and shrink, which closes the pores in the cell wall and prevents the stain from exiting the cell. At the end of the gram staining procedure, gram positive cells will be stained a purplish-blue color. Gram negative cells also take up crystal violet, and the iodine forms a crystal violet-iodine complex in the cells as it did in the gram positive cells. However, the cell walls of gram negative organisms do not retain this complex when decolorized. Peptidoglycans are present in the cell walls of gram negative organisms, but they only comprise 10-20% of the cell wall. Gram negative cells also have an outer layer which gram positive organisms do not have; this layer is made up of lipids, polysaccharides, and proteins. Exposing gram negative cells to the decolorizer dissolves the lipids in the cell walls, which allows the crystal violet-iodine complex to leach out of the cells. This allows the cells to subsequently be stained with safranin. At the end of the gram staining procedure, gram negative cells will be stained a reddish-pink color. Remember:
What are some of the reason for a Gram variable reaction?
what are some of the reasons for a gram-variable reaction
Does pH influence the gram stain reaction?
pH does not directly influence the Gram stain reaction. The Gram stain differentiates between bacterial cell wall structures based on their ability to retain or release crystal violet dye during the staining process. The process is not significantly affected by small changes in pH.
What gram reaction do you expect from acid-fast bacteria?
Gram positive
What are the two different types of cell wall found in eubacteria?
The two different types of cell walls found in eubacteria are gram-positive and gram-negative cell walls. Gram-positive cell walls have a thick layer of peptidoglycan, while gram-negative cell walls have a thinner layer of peptidoglycan surrounded by an outer membrane.
Is cell a countable or uncountable noun Do I say 1 gram of cell or 1 gram of cells?
The noun cell is a countable noun. You should say, "one gram of cells".
