What is the name of the primary stain used in the Gram staining process?

In the Gram staining process, the primary stain used is crystal violet. This stain is the first dye applied to the bacterial sample and is crucial for differentiating between Gram-positive and Gram-negative bacteria. Crystal violet penetrates the peptidoglycan layer of the cell wall in Gram-positive bacteria, leading to retention of the dye, which gives these bacteria a purple appearance after the staining procedure.

The importance of crystal violet lies in its ability to highlight the structural differences in bacterial cell walls, allowing for effective classification based on their Gram reaction. This initial staining step is followed by a mordant (iodine) that helps fix the dye, but crystal violet itself is the primary agent responsible for the initial color change observed in the bacterial cells. Other coloring agents like safranin and methylene blue are used in subsequent steps but are not part of the initial primary staining phase.