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Why gram staining procedure cannot stain endospores?
Because stains can't penetrate the spore covering. You have to heat the spore to open it and let the stain in.
What are the advantages of the simple stain technique over the negative stain technique?
Negative staining has a dark contrasted background and the bacteria is white. Simple staining has a white background and bacteria is the color depended on your stain color.Negative staining when prepared is NOT heat fixed but simple staining when prepared is heat fixed. Heat fixed means when preparing slide with bacteria on it, it is passed over some type of flame, like a Bunsen burner flame, three times or four times.
What is the purpose of emulsifying the sample serum in staining procedure?
To promote the cells adhering to the glass slide since they can't be heat fixed. When preparing a capsule stain you have to aseptically add organisms and emulsify with a loop.
Why heat the slide when performing spore stain?
Endospores are impermeable to most stains so heat is usually applied to drive the stain into the endospore.
What would you expect from a gram stain done on a slide that was heated too hot during the heat-fixed smear?
A Gram stain refers to a staining technique for the identification of bacteria. A Gram stain done on a slide that was heated too hot during the heat-fixed smear will destroy the cell wall of the bacteria.
Why gram staining procedure cannot stain endospores?
Because stains can't penetrate the spore covering. You have to heat the spore to open it and let the stain in.
What is the purpose of the heat during the acid fast staining procedure?
It acts as the mordant to soften the mycolic acid so that the stain can penetrate the cell.
What mordant is used in spore staining?
Heat is the mordant used in the spore stain, it fixes the primary stain.
What is a primary stain?
If your talking about Acid Fast staining (aka Ziehl-Neelsen staining), after the addition of the primary stain (carbol fuchsin) heat is applied in order to facilitate proper staining. Bacteria such as Mycobacterium contain large amounts of lipid substances within their cell wall called mycolic acids. These acids resist staining by ordinary methods such as gram staining (where heat is not applied after primary staining). On application of heat, the stain carbol fuschin penetrates the cell wall and stains the cells pink. Following the secondary staining (methylene blue) the acid fast positive cells appear pink while others are stained blue. Endospore staining is yet another staining technique where heat is applied after primary staining (malachite green). In this case the spores are impermeable to stains, hence heating favours proper permeation of stain. Endospores appear green while vegetative cells appear red (secondary stain saffranine). Not all staining procedures involve applying heat after primary staining. However, heat is applied before even beginning the staining procedure. This is called heat fixing, where the cells are fixed so that they are not washed away during the subsequent washing steps.
Is endospore staining differencial staining?
Endospore staining is a differential stain used to detect the presence and location of spores in bacterial cells.
Why steam heating is done in acid fast staining and not heat fixing?
Actually, both methods are used during the staining procedure (steam & heat fix). Initially, the organism is heat fixed to the slide to prevent the organism from being washed off during subsequent steps. Later in the procedure, the slide with the heat fixed organism is steamed to make the cell wall a little more penetrable - allowing the stain to enter the cell wall.
What is the purpose of staining the smear in malachite green during spore staining?
the purpose of boiling of smear in malachite green is to forces a stain to penetrate the endospore wall, it is necessary to heat the slide and the stain to prod the wall to allow the stain to enter.
What are the advantages of the simple stain technique over the negative stain technique?
Negative staining has a dark contrasted background and the bacteria is white. Simple staining has a white background and bacteria is the color depended on your stain color.Negative staining when prepared is NOT heat fixed but simple staining when prepared is heat fixed. Heat fixed means when preparing slide with bacteria on it, it is passed over some type of flame, like a Bunsen burner flame, three times or four times.
What so endospore stain have in common with the acid-fast stain?
One thing that endospore stains have in common with the acid fast stain is that heat primary stain penetration. Another thing that endospore stains have in common with acid fast stains are counterstain.
What is the purpose of emulsifying the sample serum in staining procedure?
To promote the cells adhering to the glass slide since they can't be heat fixed. When preparing a capsule stain you have to aseptically add organisms and emulsify with a loop.
What is the purpose of the heat during the staining procedures?
It acts as the mordant to soften the mycolic acid so that the stain can penetrate the cell.
Assume that during the performance of this exercise you made several errors in your spore staining procedure?
Assume that during the performance of this exercise you made several errors in your spore-staining procedure. In each of the following cases indicate how your microscopic observations would differ from those observed when the slides were prepared correctly . A. you used acid-alcohol as the decolorizing agent . B. you used safranin as the primary stain and malachite green as the counterstain C. you did not apply heat during the application of the primary stain · A. Normally tap water is used as the decolorizing agent to wash off excess stain. When you use acid-alcohol, it decolorizes the cells and the stain is removed. · B.When you use safranin as the primary stain and malachite green as the secondary stain, the cells will stain green and the spores will stain red. · C.When heat is not applied during the application of the primary stain, the spores are not stained and they appear colorless.
