How Does Counterstain Stain Work?

The dye or stain that is used to differentiate one component or cellular structure from another, or to differentiate an entity from another in a specimen. It does so by colouring a portion of a specimen (e.g. of a tissue or of a cell) that remained uncoloured following the first staining using a dye of different color.

What does the counterstain do in Gram staining?

In Gram staining, crystal violet stains only Gram-positive bacteria, and safranin counterstain is applied which stains all cells, allowing the identification of Gram-negative bacteria as well. ... Counterstains are sometimes used to separate animals from organic detritus in microbiology studies.

What are the 4 steps of Gram staining?

The performance of the Gram Stain on any sample requires four basic steps that include applying a primary stain (crystal violet) to a heat-fixed smear, followed by the addition of a mordant (Gram's Iodine), rapid decolorization with alcohol, acetone, or a mixture of alcohol and acetone and lastly, counterstaining with ...