Podcast
Questions and Answers
What is the primary stain used in the gram staining procedure?
What is the primary stain used in the gram staining procedure?
What role does the iodine solution play in gram staining?
What role does the iodine solution play in gram staining?
During which step is the decolorization of gram-negative bacteria achieved?
During which step is the decolorization of gram-negative bacteria achieved?
What color do gram-positive bacteria appear after the gram staining process?
What color do gram-positive bacteria appear after the gram staining process?
Signup and view all the answers
What is the purpose of the counterstain in gram staining?
What is the purpose of the counterstain in gram staining?
Signup and view all the answers
Which statement accurately describes the gram staining process?
Which statement accurately describes the gram staining process?
Signup and view all the answers
What is formed when iodine is added to the crystal violet in the gram staining process?
What is formed when iodine is added to the crystal violet in the gram staining process?
Signup and view all the answers
What occurs during the washing step with 95% ethanol in gram staining?
What occurs during the washing step with 95% ethanol in gram staining?
Signup and view all the answers
Study Notes
Gram Staining Procedure
- Prepare a thin bacterial smear on a slide.
- Cover the smear with crystal violet (primary stain) for a minute.
- Wash the slide with water to remove excess stain.
- Add iodine solution (mordant) for a minute.
- Rinse with water.
- Decolorize with 95% ethanol for 10-30 seconds.
- Rinse with water.
- Counterstain with safranin for a minute.
- Rinse and observe under a microscope.
Gram-Positive vs. Gram-Negative
- Gram-positive bacteria: Retain the crystal violet stain, appearing purple. Possess a thick peptidoglycan layer in their cell walls.
- Gram-negative bacteria: Lose the crystal violet stain after decolorization. They take up the counterstain (safranin), appearing pink/red. Have a thin peptidoglycan layer and an outer membrane.
Gram Staining Principle
- The process distinguishes bacteria based on differences in their cell wall structure.
- The thick peptidoglycan layer in Gram-positive bacteria traps the crystal violet-iodine complex, while the thin layer in Gram-negative bacteria allows the complex to be removed during decolorization.
Gram Staining Results
- Gram-positive: Purple
- Gram-negative: Pink/red
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Explore the Gram staining procedure, which is essential for classifying bacteria into Gram-positive and Gram-negative. This quiz covers the steps involved in the staining process, the characteristics of both types of bacteria, and the underlying principles of the method. Test your knowledge on this key microbiological technique.
