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Outline types staining process

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There are several ways of doing staining of organisims.They include;
1.Endospore staining;

Spore formation takes place in some bacterial genera to withstand unfavourable conditions. All bacteria cannot form spores, only few bacterial genera including Bacillus, Clostridium, Desulfotomaculum produce sporulating structure inside vegetative cells called endospore.

Endospore morphology and location vary with species and are valuable for identification Endospores are not stained well by most dyes, but once stained, they strongly resist decolorization.

In the Schaffer-Fulton procedure, endospores are first stained by heating bacteria with malachite green, which is very strong stain that can penetrate endospores. After malachite green treatment, the rest of the cell is washed free of dye with water and is counter-stained with safranin. This technique yields a green endospore with red vegetative cell.

2.Simple staining;
Colouration of microorganisms by applying single dye to a fixed smear is termed simple staining. One covers the fixed smear with stain for specific period, after which this solution is washed off with water and slide blotted dry. Basic dyes like crystal violet, methylene blue and carbolfuchsin are frequently used in simple staining to determine the size, shape and arrangement of prokaryotic cells.

3.Gram staining;
It is one of the most important and widely used differential staining techniques in microbiology. This technique was introduced in 1884 by Danish Physician Christian Gram.

4.Acid fast staining;
It is another important differential staining procedure. It is most commonly used to identify Mycobacterium spp. These bacteria have cell wall with high lipid content such as mycolic acid -a group of branched chain hydroxy lipids, which prevent dyes from readily binding to cells.

They can be stained by Ziehl-Nulsen method, which uses heat and phenol to derive basic fuchsin into the cells. Mycrobacterium spp. were penetrated with basic fuchsin, not easily decolourized by acidified alcohol (acid alcohol) and thus are said to be acid fast.

Non arid fast bacteria are decolourized by arid alcohol and thus are stained blue by methylene blue counter stain.

MICHAELONYINKWA answered the question on September 19, 2017 at 14:18

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