There are two major types of simple stains used to better visualize microorganisms. What are these two types of simple stains and how do they differ?

• A. Basic stain is a positively charged dye; Acidic stain is a neutral dye.
• B. Basic stain is a positively charged dye; Acidic stain is a negatively charged dye.
• C. Basic stain is an indirect stain; Acidic stain is a direct stain.

Answer: (B)

Verified step by step guidance

1. Understand the purpose of simple stains in microbiology: Simple stains are used to enhance the visibility of microorganisms under a microscope by increasing contrast.
2. Identify the two major types of simple stains: Basic stains and acidic stains.
3. Explain the charge difference: Basic stains are positively charged dyes, which means they are attracted to the negatively charged components of microbial cells, such as nucleic acids and cell walls. Acidic stains are negatively charged dyes, which repel the negatively charged components of microbial cells.
4. Clarify the staining method: Basic stains are direct stains, meaning they directly stain the cells, making them visible against a lighter background. Acidic stains are indirect stains, which stain the background and leave the cells unstained, creating a silhouette effect.
5. Summarize the key differences: Basic stains are used to stain the cells directly due to their positive charge, while acidic stains stain the background due to their negative charge, highlighting the cells indirectly.