what is the purpose of heat fixing in simple staining experi

what is the purpose of heat fixing in simple staining experiment?

Solution

Stains are chemical compounds which are useful for enhancing the visibility of the sample being viewed under the microscope, Bacteria, being microscopic in size and also mostly being colorless, requires staining in order to view them. There are different techniques of staining and stains used in microbiology, the easiest and simplest of them being the simple staining technique.

In simple staining, a drop of liquid bacterial culture is taken onto a clean slide or bacterial culture from Petri-plate can be mixed into a drop of distilled water using an inoculation loop. Now the slide is waved over a flame to carry out heat fixing. This serves two purposes:

In simple staining, usually cationic or basic dyes are used, for example, methylene blue. Since the cell wall and cytoplasm are negatively charged, the positively charged ions in the basic dye help in staining the cells effectively.