INTENDED USE
- BacterStrain™ Grams Stain Kit is used for differentiation of bacteria on the basis of their gram nature.
PRINCIPLES
- The gram staining kit consists of 4 bottles containing Crystal Violet, Safranine, Lugol (Iodine) and Alcohol (Decolourizer).
- Crystal Violet, a basic dye, is the primary stain taken up by all bacteria due to its ability to rapidly permeate the cell wall. It stains the protoplast of bacteria purple. The potassium-iodine mixture (Lugol), in gram iodine, is the mordant which complexes with the primary stain in the cell. In gram-positive cells, the crystal violet-iodine complex is trapped in the cell due to a decrease in cell wall permeability caused by alcohol dehydration. Gram-positive cells are stained purple.
- In gram-negative cells, the complex is removed by the Decolorizer due to an increase in permeability caused by solubility of the lipids in alcohol.
- The counterstain used must be a contrasting color to the primary stain and in this case it is Safranin, which stains gram-negative cells red.