Unit 2 - Learning aim C: Chromatography

Unit 2- Learning aim D: Practical Scientific Procedures
and Techniques

Aseptic Technique - ANSWER Prevents contamination of microbial cultures.

Purpose of Aseptic Technique - ANSWER Ensure purity and reliability of
experimental results.

Hand Washing - ANSWER First step in aseptic technique to prevent contamination.

Inoculation Loop Sterilization - ANSWER Flame until red to eliminate contaminants.

Labeling Samples - ANSWER Include date, name, test, and microorganism.

Gram Stain Purpose - ANSWER Identify bacteria based on cell wall structure.

Crystal Violet Staining - ANSWER First stain applied for 30 seconds.

Iodine Staining - ANSWER Used for 1 minute to fix crystal violet.

Decolorization - ANSWER Alcohol treatment for 15-30 seconds.

Counterstaining - ANSWER Safranin applied for 1 minute after decolorization.

Gram Positive Bacteria - ANSWER Retain crystal violet, appear purple.

Gram Negative Bacteria - ANSWER Do not retain crystal violet, appear red.

Acid-Fast Stain Purpose - ANSWER Detect mycolic acid in bacterial cell walls.

Heat Fixing - ANSWER Process to adhere bacteria to slides.

Rinsing Steps - ANSWER Involves water rinses after staining.

Blotting Dry - ANSWER Final step using paper towel after staining.

Microbial Contaminants - ANSWER Unwanted microorganisms affecting
experimental results.

Sterilization Techniques - ANSWER Methods to eliminate all forms of life.

Carbolfuchsin - ANSWER Stain used in acid-fast staining.

Counterstain - ANSWER Secondary stain applied after primary stain.

Acid-Fast Organisms - ANSWER Retain fuchsia stain due to mycolic acid.