Gram Staining Process: Revealing the Colors of Bacteria

What color is Staphylococcus aureus before the primary stain is added?

A. Pink

B. Purple

C. No color

Answer:

C. No color

Staphylococcus aureus appears colorless before the primary stain is added during the Gram staining process. This type of bacteria does not exhibit any color until the initial step of applying a purple dye.

Before the primary stain, which is a purple dye called crystal violet, is applied, Staphylococcus aureus remains colorless. The Gram staining technique involves applying various stains and a decolorizing agent to differentiate between Gram-positive and Gram-negative bacteria.

Once the primary stain is added, Staphylococcus aureus takes on a purple color. This color is retained even after the decolorizing step, as Staphylococcus aureus is classified as a Gram-positive bacterium.

Understanding the colors of bacteria through the Gram staining process is crucial for microbiology studies and identifying bacterial species based on their staining characteristics.