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In gram staining why will very thick smears give inaccurate results?
Wiki User
∙ 12y ago
If a smear exhibits uneven thickness, overlapping cells may not get the proper exposure to the reagents. This results in uneven or mottled staining. For example, in the thicker areas of the smear, gram-negative cells may not decolorize sufficiently and end up staining purple.
Wiki User
∙ 14y ago
Wiki User
∙ 13y agobecause if you make your smear too tinck then you will not be able to stain the bacteria correctly. the alcohol you use to decolorize your smear may not take all the primary stain away. so you may get a gram posative result when it should be gram negative.
Wiki User
∙ 12y agoa false positive result may occur from a very thick smear
Wiki User
∙ 12y agoso that it can dry quick
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Why you perform thin and thick blood smear?
Smears are prepared to study microscopic features of a specimen. If we use thisk smears, then it would be difficult to study morphologic features. That's why, thin smears are preferred over thick smears
Why are thick or dense smears less likey to provide a good smear preparation for microscopic evaluation?
Denser smears provide more obstacles for the light going through the sample, making the cells or objects you're observing more difficult to see.
Is there any difference if the prepared smear is too thick or too thin?
Thin smears of blood are needed to investigate hematological problems or disorders of the blood. It is also used to identify the parasite within the blood. Thick films enables the microscopist to screen the blood of a larger volume. They are more sensitive than the thin film.
What relationship did you find if any between the Gram-staining reaction of a microorganism and its susceptibility to antiseptics and disinfectants?
Gram + bacteria has thick cell walls. This feature makes them more resistant to antiseptic and disinfectants.
Three factors that may affect gram stain reaction?
(i) The age of bacterial culture should not be more than 24 h. At older age cell loses Gram positivity and will appear as Gram negative. (ii) Application of heat during the fixation of smears is another important step. Too much heating during this step will lead to loss in, Gram positiveness. (iii) Overcrowding of cells in smear also affects the result, due to improper decolourization. (iv) Staining reagents should be freshly prepared. (v) In Gram staining decolourizing step is very important. To obtain satisfactory differentiation, the nature and the exposure time of decolourizing agent should be standardized with the material to be stained. Acetone alone is more powerful decolourizing agent than ethanol. (vi) It is also important not to allow a .bacterial smear to dry. There are many variations of original Gram staining procedure
Why you perform thin and thick blood smear?
Smears are prepared to study microscopic features of a specimen. If we use thisk smears, then it would be difficult to study morphologic features. That's why, thin smears are preferred over thick smears
Why are thick or dense smears less likey to provide a good smear preparation for microscopic evaluation?
Denser smears provide more obstacles for the light going through the sample, making the cells or objects you're observing more difficult to see.
Why are thick or dense smears less likely to provide a good smear preparation?
because if too much smear the sample will look to indistinct
Why you do staining?
Staining is done to help determine what the sample is. It makes it visible under a microscope and it gives some information about the structure of the cell. A positive Gram stain means that the cell has a thick peptidoglycan layer.
Why is it important not to use thick or dense bacterial smears?
In a thick smear the bacteria will be too concentrated, reducing the amount of light passing through the slide, the stain may not penetrate adequately, and it will be difficult to visualize individual cells.
What is the definition of negative staining?
negative staining is when the micro-organism on slide is not stained.. instead the rest of the material on the slide gets stained and the organism stands out prominently unstained.. this occurs because that organism has a thick capsule around it which is non-stainable with that stain.. example is pneumococci staining with India ink.
What is the gram stain results for an L. lactus bacteria?
Lactococcus Lactus is a gram positive bacteria and therefore retains the darker staining and therefore shows on a gram stain as dark blue/violet colour. This is because the thick peptidoglycan cell wall retains the primary crystal violet stain.
Is there any difference if the prepared smear is too thick or too thin?
Thin smears of blood are needed to investigate hematological problems or disorders of the blood. It is also used to identify the parasite within the blood. Thick films enables the microscopist to screen the blood of a larger volume. They are more sensitive than the thin film.
What is it called when the defective protein that results in the production of excessive amounts of thick mucus?
Cystic Fibrosis
What relationship did you find if any between the Gram-staining reaction of a microorganism and its susceptibility to antiseptics and disinfectants?
Gram + bacteria has thick cell walls. This feature makes them more resistant to antiseptic and disinfectants.
Three factors that may affect gram stain reaction?
(i) The age of bacterial culture should not be more than 24 h. At older age cell loses Gram positivity and will appear as Gram negative. (ii) Application of heat during the fixation of smears is another important step. Too much heating during this step will lead to loss in, Gram positiveness. (iii) Overcrowding of cells in smear also affects the result, due to improper decolourization. (iv) Staining reagents should be freshly prepared. (v) In Gram staining decolourizing step is very important. To obtain satisfactory differentiation, the nature and the exposure time of decolourizing agent should be standardized with the material to be stained. Acetone alone is more powerful decolourizing agent than ethanol. (vi) It is also important not to allow a .bacterial smear to dry. There are many variations of original Gram staining procedure
Why some bacteria cannot be stained by grams method of staining?
Instead of one thick cell wall made of peptidoglycan they may have two thinner cell walls and the stain does not stick and is washed away.
