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Which step can be omitted without affecting determination of the Gram reaction Why?
Gram Staining
| Question | Answer |
|---|---|
| can iodine be added before the primary stain in gram stain? | No, it must complex with primary stain |
| which step can be omitted without affecting determination of the gram reaction | the counter stain safranin as differentiation can still be made |
What step can be skipped in Gram staining?
Mordant step
Mordant step skipped: Gram-positive bacteria will appear Gram-negative. 4. Slide not decolorized: Gram-negative bacteria will appear Gram-positive.
What factors can affect the Gram stain reaction?
The many variables that can affect this stain are age of the culture, amount of decolorizer used, the time of decolorization, the type of organism (acid-fast bacteria and spores do not stain well), thickness of the smear, and the general care of the stainer.
Which step in the Gram stain procedure is most prone to error if done incorrectly How might that step affect the end result?
Which step in the gram stain procedure is most prone to error? If done incorrectly, how might that step affect the end result? Too much decolorizer = g+ lose initial stain.
What happens without safranin in Gram staining?
A safranin counterstain is used to stain these Gram-negative cells pink. However, if the safranin counterstain were forgotten, the Gram-negative bacteria would remain unstained, as the original crystal violet stain would have been removed during the ethanol wash, and no additional stain would have been applied.
What are the steps of Gram staining?
The performance of the Gram Stain on any sample requires four basic steps that include applying a primary stain (crystal violet) to a heat-fixed smear, followed by the addition of a mordant (Gram’s Iodine), rapid decolorization with alcohol, acetone, or a mixture of alcohol and acetone and lastly, counterstaining with …
Which step in the Gram stain is most likely to cause poor results if done incorrectly?
The decolorization of the cells is the most “operator-dependent” step of the process and the one that is most likely to be performed incorrectly. Rinse with water to stop decolorization. Rinse the slide with a counterstain (safranin or carbol fuchsin) which stains all cells red.
When performing a Gram stain which step in the staining procedure is most likely to cause a poor result Why?
It is clear that the decolorization step is the one most likely to cause problems in the Gram stain. The particular concerns in this step are listed below. Heat fixing the cells, when done to excess, alters the cell morphology and makes the cells more easily decolorized.
Which step in the Gram stain is the critical step in differentiating?
The thickness of the smear used in the Gram stain will affect the result of the stain. The step that is most crucial in effecting the outcome of the stain is the decolorizing step.