Microbiology Lab Practical #1 Review
Questions and Answers 100% Pass
Bacterial Smear - ✔✔Allows better visualization of specimens using microscopy.
Heat Fixing - ✔✔kills organisms, keeps organisms stuck to slide, allows the specimen to
be stained more easily
Aseptic Technique - ✔✔preparing and handling sterile products in a manner that
prevents microbial contamination
Gram Staining Procedure - ✔✔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
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, 8. Rinse with distilled water
9. Blot dry with Bibulous paper, observe under oil immersion and record results
Capsule Stain Procedure - ✔✔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
Why do you not heat fix during the capsule stain procedure? - ✔✔Heat will cause the
capsule to dislodge
Why do you not rinse with water during the capsule stain procedure? - ✔✔Water will
remove the capsule from the cell
Why do you not blot during the capsule stain procedure? - ✔✔Blotting will remove the
bacteria from the slide and/or distort the capsule
Katelyn Whitman, All Rights Reserved © 2025 2
Questions and Answers 100% Pass
Bacterial Smear - ✔✔Allows better visualization of specimens using microscopy.
Heat Fixing - ✔✔kills organisms, keeps organisms stuck to slide, allows the specimen to
be stained more easily
Aseptic Technique - ✔✔preparing and handling sterile products in a manner that
prevents microbial contamination
Gram Staining Procedure - ✔✔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
Katelyn Whitman, All Rights Reserved © 2025 1
, 8. Rinse with distilled water
9. Blot dry with Bibulous paper, observe under oil immersion and record results
Capsule Stain Procedure - ✔✔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
Why do you not heat fix during the capsule stain procedure? - ✔✔Heat will cause the
capsule to dislodge
Why do you not rinse with water during the capsule stain procedure? - ✔✔Water will
remove the capsule from the cell
Why do you not blot during the capsule stain procedure? - ✔✔Blotting will remove the
bacteria from the slide and/or distort the capsule
Katelyn Whitman, All Rights Reserved © 2025 2
