Micro Lab Final Questions and Verified Answers
Gram (+) has a thicker cell wall; what does it do in a gram stain? Correct Answer: It retains the crystal
violet dye
Alpha Correct Answer: Partial Hemolysis-Greenish color
S. Pneumoniae
Beta Correct Answer: Complete Hemolysis-Clear yellowish ring
S. Pyogenes
S. Aureus
Bacillus Subtillus
Gamma Correct Answer: No Hemolysis-No change
S. Epidermis
Mannitol Salt Agar (Selective) Correct Answer: Used to isolate Staphylococcal
(S. aureus will ferment and cause Yellow appearance)
(S. Epidermis will remain red;Phenol Red)
Glucose Fermentation Broth (PRB) Correct Answer: Phenol red will change to Yellow if (+); and carbs &
sugars are fermented.
Catalase Test (Differential) Correct Answer: -tests different types of bacteria
(+) = bubbles
(streptococcus is - result)
Coagulase Test Correct Answer: In a plastic tube w/ a blue top.
Gram (+) has a thicker cell wall; what does it do in a gram stain? Correct Answer: It retains the crystal
violet dye
Alpha Correct Answer: Partial Hemolysis-Greenish color
S. Pneumoniae
Beta Correct Answer: Complete Hemolysis-Clear yellowish ring
S. Pyogenes
S. Aureus
Bacillus Subtillus
Gamma Correct Answer: No Hemolysis-No change
S. Epidermis
Mannitol Salt Agar (Selective) Correct Answer: Used to isolate Staphylococcal
(S. aureus will ferment and cause Yellow appearance)
(S. Epidermis will remain red;Phenol Red)
Glucose Fermentation Broth (PRB) Correct Answer: Phenol red will change to Yellow if (+); and carbs &
sugars are fermented.
Catalase Test (Differential) Correct Answer: -tests different types of bacteria
(+) = bubbles
(streptococcus is - result)
Coagulase Test Correct Answer: In a plastic tube w/ a blue top.
