2025-2026 SERIES
MICROBIOLOGY LAB PRACTICAL #1 REVIEW
COMPLETE QUESTIONS AND CORRECT ANSWERS |
GRADED AND THE LATEST SERIES
Bacterial Smear
Ans: Allows better visualization of specimens using microscopy.
Question: Heat Fixing
Ans: kills organisms, keeps organisms stuck to slide, allows the specimen to be
stained more easily
Question: Aseptic Technique
Ans: preparing and handling sterile products in a manner that prevents microbial
contamination
Question: Gram Staining Procedure
, 2025-2026 SERIES
Ans: 1. Heat fix bacterial smear
2. Cover with Crystal Violet (Primary Stain) and wait 60 seconds
3. Rinse slide with distilled water until stain is removed
4. Cover with Gram's Iodine (Mordant) and wait for 60 seconds
5. Rinse with distilled water
6. 2-3 drops of Decolorizer (95% Ethanol), or until color is clear, rinse with distilled
water
7. Cover with Safranin (Counter Stain) and wait 45 seconds
8. Rinse with distilled water
9. Blot dry with Bibulous paper, observe under oil immersion and record results
Question: Capsule Stain Procedure
Ans: 1. Agitate broth culture
2. 2-3 loop fulls of broth culture added to slide and allow to air dry (NOT HEAT
FIXING)
3. Cover with Crystal Violet (Primary Stain) and wait for 2 minutes
4. Rinse with 20% Copper Sulfate Solution (Decolorizer and counter stain)
5. DO NOT RINSE WITH WATER
6. Air dry for a few minutes and DO NOT BLOT
Observe under oil immersion and record results
Question: Why do you not heat fix during the capsule stain procedure?
Ans: Heat will cause the capsule to dislodge
Question: Why do you not rinse with water during the capsule stain procedure?
MICROBIOLOGY LAB PRACTICAL #1 REVIEW
COMPLETE QUESTIONS AND CORRECT ANSWERS |
GRADED AND THE LATEST SERIES
Bacterial Smear
Ans: Allows better visualization of specimens using microscopy.
Question: Heat Fixing
Ans: kills organisms, keeps organisms stuck to slide, allows the specimen to be
stained more easily
Question: Aseptic Technique
Ans: preparing and handling sterile products in a manner that prevents microbial
contamination
Question: Gram Staining Procedure
, 2025-2026 SERIES
Ans: 1. Heat fix bacterial smear
2. Cover with Crystal Violet (Primary Stain) and wait 60 seconds
3. Rinse slide with distilled water until stain is removed
4. Cover with Gram's Iodine (Mordant) and wait for 60 seconds
5. Rinse with distilled water
6. 2-3 drops of Decolorizer (95% Ethanol), or until color is clear, rinse with distilled
water
7. Cover with Safranin (Counter Stain) and wait 45 seconds
8. Rinse with distilled water
9. Blot dry with Bibulous paper, observe under oil immersion and record results
Question: Capsule Stain Procedure
Ans: 1. Agitate broth culture
2. 2-3 loop fulls of broth culture added to slide and allow to air dry (NOT HEAT
FIXING)
3. Cover with Crystal Violet (Primary Stain) and wait for 2 minutes
4. Rinse with 20% Copper Sulfate Solution (Decolorizer and counter stain)
5. DO NOT RINSE WITH WATER
6. Air dry for a few minutes and DO NOT BLOT
Observe under oil immersion and record results
Question: Why do you not heat fix during the capsule stain procedure?
Ans: Heat will cause the capsule to dislodge
Question: Why do you not rinse with water during the capsule stain procedure?
