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Its the primary stain of the procedure. IT stains the Gram positive organisms
Its the primary stain of the procedure. IT stains the Gram positive organisms
Both processes use 2 stains. The Gram staining process uses crystal violet as the primary stain and safranin as the secondary stain. Acid-fast staining uses carbol fuchsin as the primary and methylene blue as the secondary.
In a gram stain the primary stain is crystal violet. Iodine then sets that dye into the gram positive cells while alcohol washes out the crystal violet from the gram negative cells. Then safranin, which is the counterstain in a gram stain, is used to dye the rest of the bacteria. This is the example I can give you of why a counterstain does not change the look in all the cells. Though safranin stains all the cells, the gram positive cells that were dyed purple from crystal violet don't look pink - only the gram negative do.
Gram's iodine stain is applied after the culture is stained with the primary stain. It acts as a mordant, fixing the primary stain to the cell wall while lending no additional colour to the cell (i.e. the mordant itself is not a stain). The mordant is only able to fix the stain to Gram-positive bacteria because of the characteristic thick, peptidoglycan coat that they possess. Because the mordant is not able to fix the stain to Gram-negative bacteria (who's coat have a different composition), the crystal violet stain will wash away from Gram-negative bacteria when the decolourizing agent is added.
A gram stain is a cow
capsule
The gram stain uses a decolorizing product so it is possible to differentiate between the gram and the gram cells. Gram positive cells stain purple in color.
Lactococcus Lactus is a gram positive bacteria and therefore retains the darker staining and therefore shows on a gram stain as dark blue/violet colour. This is because the thick peptidoglycan cell wall retains the primary crystal violet stain.
Gram stain
It is crystal violet & stains all cells purple.
Gram Negative