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Why should you be careful not to under heat a smear during the heat fixing process?
* Overheat will denature and rupture the cell wall. * Excess water on the slides will boil during fixation. Why should you be careful not to overheat the smear during the heat-fixing process? Yes, the simple staining shows clear cell form and structure and allows individual to view arrangement of appearance of cells.
Do not heat the slide to speed drying why?
Completely air-dry the slide, without applying heat. This should not take long because there is not much liquid on the slide anyway. If you heat the slide before it is completely dry, then you end up “boiling apart” the cells.
Why is heat fixing not proper on smear that is not completely dried?
DO NOT HEAT FIX WET SLIDES. If slides are not dried completely the water will boil on the slide and in the cells and distort shape of the bacteria. Heat fixing kills the bacteria and makes them adhere to the slide throughout the staining process. 3.
Why is it necessary to heat fix the smear?
Heat fixing kills the bacteria in the smear, firmly adheres the smear to the slide, and allows the sample to more readily take up stains.
What is the purpose of fixing the smear by heat?
Heat fixing kills cells, and adheres them to the slide. Cells will be rinsed off the slides if they are not heat fixed properly.
Why is a heat smear air dry?
What is the purpose of allowing the bacterial smear to dry once it has been placed onto the surface of the slide? Drying helps remove excess water to ensure optimal heat fixation. Air-drying adheres the bacteria to the slide. Air-drying ensures that the smear is thin enough to stain.
Why are smears air dried?
Overlapping organisms are hard to identify and diminishes the amount of light that can pass through and makes it difficult to visualize the morphology of single cells. Why is it essential that smears be air-dried? It may prevent the organisms from being fixed to the slide and wash away during staining process.
Why are smears heat fixed?
Heat fixation ensures the elimination of contaminating organisms from the smear preparation. Heat fixation adheres the cells to the slide and coagulates the bacterial proteins, effectively killing the bacteria.
Why is it necessary to heat fix a smear before staining?
What is the purpose of forming a smear of cells and heat fixing them on the glass slide?
The preparation of a smear is required for many laboratory procedures, including the Gram-stain. The purpose of making a smear is to fix the bacteria onto the slide and to prevent the sample from being lost during a staining procedure. A smear can be prepared from a solid or broth medium.
What would happen if no heat fixing were done?
The real problem is this: Heat fixing will stick the bacteria to the slide. Thus, if you do not heat fix, it is extremely likely that you will wash off your bacteria, leaving little to none to be seen under the microscope.