Bacterial Staining Techniques Quiz

Bacterial ______ is necessary to make them readily visible for observation of intracellular structures

Negative staining is good for viewing bacterial ______

Negative, indirect, or background staining is achieved by mixing bacteria with an acidic ______

Stains like nigrosin, India ink, or eosin produce a deposit around the bacteria or a dark ______

Negative staining makes bacteria appear as unstained cells with a clear area around them due to repulsion between the negative charge of the stains and the negatively charged bacterial ______

Negative staining allows determination of overall bacterial morphology without the use of harsh staining or heat-fixing techniques that change the shape of ______

Bacterial Staining

Bacterial staining is necessary to make bacteria visible for observation of intracellular structures and overall morphology because living bacteria are generally colorless and invisible.

Types of Bacterial Staining

Negative stain: used to determine overall bacterial morphology without using harsh staining or heat-fixing techniques.
Simple stain: no specific information provided.
Differential stain: no specific information provided.
Gram stain: no specific information provided.
Capsule stain: no specific information provided.
Acid-fast stain: no specific information provided.
Endospore stain: no specific information provided.
Flagella stain: no specific information provided.

Negative Staining

Principles:
- Achieved by mixing bacteria with an acidic stain (e.g., nigrosin, India ink, or eosin).
- The acidic stain does not penetrate and stain the bacterial cells due to repulsion between the negative charge of the stains and the negatively charged bacterial wall.
- Instead, the stain produces a deposit around the bacteria or a dark background, making the bacteria appear as unstained cells with a clear area around them.
Procedure: as shown in Figure 1.