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Difference between the gram stain ans acid fast stain reactions of E. coli?
Gram staining is useful in separating bacteria into two groups: Gram positive or Gram negative. They are separated into these groups based on their cell wall structure. Gram positive bacteria contain a thick layer of peptidoglycan in their cell walls, while Gram negative bacteria contain a very small layer of peptidoglycan (15% or less of what Gram positive cell walls contain). A primary stain is added, such as Crystal Violet, that will stain all of the bacteria. Then, a mordant (such as iodine and potassium iodide) is added to form a complex between the peptidoglycan and the stain, which will make the cell more resistant to decolorization. Then, a decolorizing agent is added, which will remove the primary stain from Gram negative bacteria, but will cause the cell walls in Gram positive bacteria to dehydrate, and therefore, they will retain the primary stain. Finally, a counterstain (typically safranin) is added to distinguish Gram positive from Gram negative. Gram positive cells will be purple, and Gram negative cells will be red if Crystal Violet and Safranin are used.Acid-fast staining is entirely different. Is is used to detect species of bacteria in the genera Mycobacteria and Nocardia. These bacteria are resistant to typical staining procedures, such as Gram staining, due to a thick, waxy lipid layer in the cell wall composed of mycolic acid. Heating of the bacteria with a very strong stain such as carbol-fuchsin is necessary to "melt" this lipid layer, and force the stain through the cell wall. Once the bacteria has cooled, they will be incredibly resistant to decolorization. Non-acid fast bacteria do not contain this mycolic acid layer, and therefore, they will decolorize much easier, and are then stained with a counterstain to distinguish Acid-Fast bacteria from Non-Acid-Fast bacteria.
What is the mordant in a gram stain?
Gram's iodine stain is applied after the culture is stained with the primary stain. It acts as a mordant, fixing the primary stain to the cell wall while lending no additional colour to the cell (i.e. the mordant itself is not a stain). The mordant is only able to fix the stain to Gram-positive bacteria because of the characteristic thick, peptidoglycan coat that they possess. Because the mordant is not able to fix the stain to Gram-negative bacteria (who's coat have a different composition), the crystal violet stain will wash away from Gram-negative bacteria when the decolourizing agent is added.
Is the disease Lyme disease gram stain positive?
Spirochetes are not considered Gram positive or Gram negative. They tend to stain pink due to the last safrinin dye in the staining process, but its cell wall structure should make it Gram negative.
What are bacteria that make ammonia?
Bacteria that make ammonia are gram-negative anaerobes.
What is the importance of gram positive and gram negative bacteria?
Typical gram-positive bacteria are those staphylococci that produce boils; typical gram-negative bacteria are the bacilli that cause whooping cough; typical gram-variable bacteria are the bacilli that cause tuberculosis.
Which thing make gram positive bacteria to get stain?
the smooth part of the cell wall make it to get stain
Difference between the gram stain ans acid fast stain reactions of E. coli?
Gram staining is useful in separating bacteria into two groups: Gram positive or Gram negative. They are separated into these groups based on their cell wall structure. Gram positive bacteria contain a thick layer of peptidoglycan in their cell walls, while Gram negative bacteria contain a very small layer of peptidoglycan (15% or less of what Gram positive cell walls contain). A primary stain is added, such as Crystal Violet, that will stain all of the bacteria. Then, a mordant (such as iodine and potassium iodide) is added to form a complex between the peptidoglycan and the stain, which will make the cell more resistant to decolorization. Then, a decolorizing agent is added, which will remove the primary stain from Gram negative bacteria, but will cause the cell walls in Gram positive bacteria to dehydrate, and therefore, they will retain the primary stain. Finally, a counterstain (typically safranin) is added to distinguish Gram positive from Gram negative. Gram positive cells will be purple, and Gram negative cells will be red if Crystal Violet and Safranin are used.Acid-fast staining is entirely different. Is is used to detect species of bacteria in the genera Mycobacteria and Nocardia. These bacteria are resistant to typical staining procedures, such as Gram staining, due to a thick, waxy lipid layer in the cell wall composed of mycolic acid. Heating of the bacteria with a very strong stain such as carbol-fuchsin is necessary to "melt" this lipid layer, and force the stain through the cell wall. Once the bacteria has cooled, they will be incredibly resistant to decolorization. Non-acid fast bacteria do not contain this mycolic acid layer, and therefore, they will decolorize much easier, and are then stained with a counterstain to distinguish Acid-Fast bacteria from Non-Acid-Fast bacteria.
What is the mordant in a gram stain?
Gram's iodine stain is applied after the culture is stained with the primary stain. It acts as a mordant, fixing the primary stain to the cell wall while lending no additional colour to the cell (i.e. the mordant itself is not a stain). The mordant is only able to fix the stain to Gram-positive bacteria because of the characteristic thick, peptidoglycan coat that they possess. Because the mordant is not able to fix the stain to Gram-negative bacteria (who's coat have a different composition), the crystal violet stain will wash away from Gram-negative bacteria when the decolourizing agent is added.
How would the pH of the stain methylene blue affect the staining of bacteria?
the ph of the stain on the bacteria caused by methylene blue would not affect it a lot since all methylene blue is supposed to do is make it visible on the microscope for e.g.
Is the disease Lyme disease gram stain positive?
Spirochetes are not considered Gram positive or Gram negative. They tend to stain pink due to the last safrinin dye in the staining process, but its cell wall structure should make it Gram negative.
What is the function of safranin in the Gram staining process?
Crystal violet is used first to stain all bacteria purple. However, when you immerse the bacteria then in alcohol, alcohol affects the permeability of the peptidoglycan layer to crystal violet, blocking its exit from gram-positive cells. This way, gram-positive cells remain purple while gram-negative cells are colourless. Safranin red is then used as a counterstain to make the two types of bacteria more differentiable.
What are bacteria that make ammonia?
Bacteria that make ammonia are gram-negative anaerobes.
Chemical sometimes used to make the specimen visible?
Stain
Would it be useful to perform a gram stain on a mixed culture?
The purity of a culture of bacteria is important so it can test on that one type of bacteria. Gram staining can be good so you make sure everything in the streak plate is one color showing that it is gram positive and gram negative.
What is the difference between a simple and a differential stain?
THE DIFFERENTIAL STAIN, SUCH AS THE GRAM STAIN, STAINS THE CELL WALL OF GRAM POSITIVE BACTERIA, DUE TO THE HIGH LEVEL OF PEPTIDOGLYCAN PRESENT IN THE CELL WALL, THESE WILL BE PURPLE IN COLOR. THOSE THAT STAIN GRAM NEGATIVE, DO NOT HAVE AS MUCH PEPTIDOGLYCAN IN THEIR CELL WALL AND WILL RETAIN NEGLIBLE AMOUNTS OF THE CRYSTAL VIOLET AND MORE OF THE SAFFRIN. HENCE THOSE WILL BE GRAM NEGATIVE OR RED TO PINK. THUS THIS TYPE OF STAIN DIFFERENTIATES THE BACTERIA IN TO TWO BASIC CATEGORIES. THIS ASSISTS THE PHYSICIAN IN MAKING A CHOICE REGARDING ANTIBIOTICS TO TREAT THE PATHOGEN WITH. A SIMPLE STAIN JUST SHOWS THE BASIC MORPHOLOGY OF THE BACTERIUM OR BACTERIA PRESENT. YOU MAY WISH TO USE BROMTHYMOL GREEN, CRYSTAL VIOLET... ETC. ALL YOU ARE LOOKING AT IS MORPHOLOGY. HOPE THAT HELPS
Construct a Venn diagram to illustrate the similarities and differences between gram positive gram negative cells?
Not really possible to make a venn diagram, but here's a list: Similarities: In Bacteria Involve a peptidoglycan layer Differences Gram-negative is much more toxic Gram-negative is crystal violet in the Gram stain while Gram-positive is red
Why must fresh bacterial cultures be used in a Gram stain?
Why must young cultures be used when doing a Gram stain Young cultures must be used so the crystal violet can stick to the cell walls of Gram positive bacteria. The cell walls break down in old cultures and the staining process is not accurate
