Question

multiple choice question
in this image, cells are illustrated as they would appear after each step of the gram stain procedure. all cells appear the same color after the first step because the ______

• first dye, crystal violet, stains all cells purple
• staining procedure has been done incorrectly
• first dye, safranin, stains all cells purple
• counterstain has not yet been applied

Explanation:

The first step of the Gram stain uses crystal violet, a primary dye that imparts a purple color to all bacterial cells, regardless of their Gram type. The differential steps (decolorization and counterstaining with safranin) come later to distinguish Gram-positive and Gram-negative cells.

Answer:

A. first dye, crystal violet, stains all cells purple