Question

explain the importance of 75% and 95% alcohol concentration during staining preocedures

Answer 1

Alcohol is a chemical agent suggested to be used in qualitative procedures to differentiate gram-negative from gram-positive organisms. A decolorizer like ethyl alcohol or dissolvent is more to the sample, that dehydrates the peptidoglycan layer, shrinking and modification it. The big crystal violet-iodine advanced isn't able to penetrate this tightened peptidoglycan layer, and is therefore at bay within the cell in Gram positive bacterium. Gram-negative cell walls contain a high concentration of lipids that square measure soluble in alcohol. The decolorizer dissolves the lipids, increasing cell-wall porousness and permitting the crystal violet-iodine advanced to effuse of the cell. the colour of the stain should distinction therewith of the first stain.