In order to prepare an optimal heat-fixed bacterial smear for staining, one must be aware of a couple of factors that may lead to poor results; briefly explain these. Why is it necessary to heat fix a smear for simple staining?

The answer is below

Explanation:

Some of the factors that may lead to poor results in an optimal heat-fixed bacterial smear for staining are the following:

1.  Thickness of the smear: In a situation whereby the smear is too thick, it would be impossible to perform adequate decolorization.

2. Quantity of Decolorizer: if the quantity of the decolorizer or reagent is concentrated, the quality of the stain will be affected

3.  Age of the culture: Older cultures have multiple ruptured and dead cells, which result in staining Gram-negative.

4. Duration of Decolorization:  Overheated smear during heat fixing, often leads to the rupture of cell walls.

The reason it is necessary to heat fix a smear for simple staining is that:

Heat fixing affects bacterial enzymes original state, which hinders their cell digestion parts, thereby leading to the breaking of the cell. The heat also improves the steadfastness of bacterial cells to the slide.