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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-.
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.
Is it feasible to determine motility using a side prepared by the Gram Stain techniques?
Bacteria are hard to see if they are not stained, but if you stain them they are dead, so motility can not be determined.
Why is counterstaining necessary when using a differential staning technique such as the gram stain?
The counter-stain allows you to see all the structures that were not stained with the primary stain. Without the counter-stain, all you would see is the purple-stained structures (nucleus, some cytoplasmic proteins), but you would have a difficult time observing the cell membrane and many cytoplasmic structures.
How bacteria help in making curd?
curd contain lactobacillus which can be stained with simple stain i.e. methylene blue which will stain it in blue colour and also can be stained with gram stain as lactobacillus is gram +ve so it will give again blue colour in gram stain.
Which stain would be the best choice for detecting mycobacterium the bacteria responsible for tuberculosis and leprosy?
ZN 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-.
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.
Describe the microscopic appearance of encapsulated streptococcus if stained with safranin?
Safranin (red) is used in gram staining and endospore staining as the secondary stain. Nigrosin is used in negative staining, staining only the background and not the bacteria. Therefore, the bacteria within the capsule would stain red from the safranin. (Like in endospore staining and negative gram staining, safranin would stain the bacteria red.) Nigrosin would stain the background of the organism just as it would in negative staining. Bacteria (within capsul): stained safranin red Capsule (outer layer of bacteria): clear Background of organism: stained dark with Nigrosin
Is it feasible to determine motility using a side prepared by the Gram Stain techniques?
Bacteria are hard to see if they are not stained, but if you stain them they are dead, so motility can not be determined.
What is there in the structure of bacteria that cause some to stain purple and other to stain 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.
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 counterstaining necessary when using a differential staning technique such as the gram stain?
The counter-stain allows you to see all the structures that were not stained with the primary stain. Without the counter-stain, all you would see is the purple-stained structures (nucleus, some cytoplasmic proteins), but you would have a difficult time observing the cell membrane and many cytoplasmic structures.
How bacteria help in making curd?
curd contain lactobacillus which can be stained with simple stain i.e. methylene blue which will stain it in blue colour and also can be stained with gram stain as lactobacillus is gram +ve so it will give again blue colour in gram stain.
Methylene blue can be prepared as a basic stain or an acidic stain. How would the pH affect the staining of bacteria?
# The pH will determine if the bacteria will have a particular charge. If the chromophore is a positive ion like the methylene blue in the equation shown in the reading, the stain is considered a basic stain; if it is a negative ion, it is an acidic stain. Most bacteria are stained when a basic stain permeates the cell wall and adheres by weak ionic bonds to the negative charges of the bacterial cell.
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
What is an azurophil?
An azurophile is a cell which has been readily stained with an azure stain.
