Lab Quiz #4 (Practical)

Enumerate the steps of aseptic technique (i.e. bacterial transfer from a nutrient broth to an agar plate). Write legibly. (12 Steps)

• 1. Sterilize the inoculating loop in the flame until it is red hot

• 2. Pick up the nutrient broth tube by the glass

• 3. Remove the cap without setting it down

• 4. Flame the mouth of the test tube

• 5. Insert the sterile loop into the broth and obtain the bacterial sample

• 6. Flame the mouth of the test tube again

• 7. Replace the cap on the test tube

• 8. Set the broth tube down

• 9. Open the sterile agar plate 

• 10. Transfer/streak the bacteria onto the agar surface with the loop

• 11. Close the agar plate

• 12. Sterilize the loop again until red hot

Gram Stain:

Color of Bacteria

Pink/Red = Gram-Negative

Purple = Gram-Positive

Gram Stain:
(Morphology/SHAPE of Bacteria)

Coccus (spherical/round)

Gram Stain:
(Morphology/SHAPE of Bacteria)

Bacillus (rod-shaped)

Gram Stain:
(Morphology/SHAPE of Bacteria)

Spiral (curved)

Gram Stain:
(Morphology/SHAPE of Bacteria)

Vibrio (comma-shaped)

Steps For Gram Stain (15 Steps)

1. Mark Slide

2. Aseptic Technique

3. Transfer Bacteria Into Slide

4. Air Dry For 1 Minute

5. Heat Fix

6. Add Crystal Violet (Leave For 1 Minute)

7. Rinse With DI Water

8. Add Iodine (Leave For 1 Minute)

9. Rinse With DI Water

10. Wash With 15 Drops of Acetone-Alcohol

11. Rinse With DI Water

12. Add Safranin (Leave For 1 Minute)

13. Rinse With DI Water

14. Blot Dry

15. Microscope

Gram Stain:
(Arrangement of Bacteria)

single

individual cells

Gram Stain:
(Arrangement of Bacteria)

Diplo

pairs

Gram Stain:
(Arrangement of Bacteria)

Strepto

Chains

Gram Stain:
(Arrangement of Bacteria)

Staphylo

Irregular (grape-like) clusters