SM Laboratory Techniques & Quality Control — Questions and Answers
Question 1: Which method is commonly used for sterilizing microbiological media?
- Filtration
- Autoclaving (Correct answer)
- UV irradiation
- Refrigeration
Correct answer: Autoclaving
Autoclaving is the most effective method for sterilizing microbiological media, using high-pressure steam to kill all microorganisms.
Question 2: What is the purpose of a Gram stain in microbiology?
- To detect fungal infections
- To differentiate bacterial cell wall types (Correct answer)
- To measure bacterial motility
- To identify viral particles
Correct answer: To differentiate bacterial cell wall types
Gram staining differentiates bacteria into Gram-positive and Gram-negative based on their cell wall composition, aiding in identification and treatment selection.
Question 3: Why is aseptic technique important in microbiology laboratories?
- To increase bacterial growth
- To prevent contamination and maintain accuracy (Correct answer)
- To improve staining procedures
- To speed up microbial identification
Correct answer: To prevent contamination and maintain accuracy
Aseptic techniques prevent contamination of microbial cultures and ensure accurate experimental results.
Question 4: What is a critical step in quality control of microbiological media?
- Skipping sterilization
- Ensuring sterility before use (Correct answer)
- Using expired media
- Storing media at room temperature indefinitely
Correct answer: Ensuring sterility before use
Ensuring sterility of prepared media prevents contamination and ensures reliable experimental results.
Question 5: Which control measure is used to verify accuracy in microbiological testing?
- Ignoring test deviations
- Using positive and negative controls (Correct answer)
- Only using experimental samples
- Avoiding calibration of equipment
Correct answer: Using positive and negative controls
Using positive and negative controls ensures that microbiological tests produce valid and reproducible results.
Question 6: Why is regular calibration of laboratory instruments important?
- To increase testing speed
- To ensure accuracy and consistency (Correct answer)
- To reduce equipment costs
- To eliminate human errors
Correct answer: To ensure accuracy and consistency
Regular calibration of instruments like spectrophotometers and incubators ensures accuracy and consistency in microbiological testing.
SM Laboratory Techniques & Quality Control
Which method is commonly used for sterilizing microbiological media?