Micro Lab 2

Question 1

catalase tests for

Answer 1

• breakdown of hydrogen peroxide
• distinguish staph vs strep
• bubbles if positive

Question 2

coagulase tests for

Answer 2

• s. aureus vs. s. epidermis
• conversion of fibrinogen to fibrin
• makes clumps

Question 3

oxidase tests for

Answer 3

• bacteria that produce cytochrome oxidase
• distinguish Neiseria spp, Pseudomonas spp, and M. catarrhalis
• positive turns purple

Question 4

alpha hemolysis

Answer 4

• partial RBC distruction

- green

Question 5

beta hemolysis

Answer 5

• complete RBC destruction

Question 6

gamma hemolysis

Answer 6

• no RBC distribution

Question 7

optochin sensitivity

Answer 7

• P disc
• distinguish S. pneumoniae from other alpha hemolytic Strep
  OPSPSA

Question 8

bacitracin sensitive

Answer 8

• A disc
• distinguish group A strep from other beta hemolytic Strep species
  BAGAB

Question 9

bile esculin test

Answer 9

• distinguish E. faecalis from other gamma hemolytic

- positive hydrolyze esculin to yield black complex