Exercise 32: Unknown Identification-----------Unknown Tube #_______

Use good aseptic technique to maintain pure cultures!!

Day 1:

A. Do Gram stain. Record results. Gram reaction______ Cell morphology _______________________ Cell grouping_______________________

B. Inoculate streak plates

C. Inoculate PR-glucose, PR-sucrose, and PR-lactose.

Day 2:

A. Observe streak plates. Describe colony morphology______________________________________ _________________________________________________________________________

B. Do catalase on streak plate (only for gram positive cocci). Catalase result __________________

C. Observe results of PR-broths. Inoculate only those media needed according to the flowchart below and the results of your PR-broths. (That will be either MR, VP, and I or urea.)

Day 3: Record results of final set of media below. Identify your unknown organism.

Gram reaction: Gram negative bacilli, Gram positive bacilli, or Gram positive cocci? Organism(s) eliminated by this result:

PR glucose: positive or negative? Organism(s) eliminated by this result:

Catalase: positive or negative? Organism(s) eliminated by this result:

PR lactose: positive or negative? Organism(s) eliminated by this result:

PR sucrose: positive or negative? Organism(s) eliminated by this result:

Urea: positive or negative? Organism(s) eliminated by this result:

MR+, VP-, I+: Which organism likely?

MR-, VP+, I-: Which organism likely?