1. Unknowns

2. 1st lab session Two unknown slants
One is gram+ and the other is gram -.
Unknowns will be numbered
Inoculate each unknown on to a Brain Heart Infusion Agar (BHIA) – subculture
(working culture)
2. Inoculate each unknown on MacConkey
Agar – do streaking for isolation
Gram staining on each unknown
Label the plates, slides, tubes with the appropriate unknown numbers.
Incubate all at 37oC

3. 2nd lab session Examine MacConkey for growth No growth – gram positive
Growth – gram negative
These results will confirm the gram staining results
Do catalase test only on gram positive unknown
Catalase + Staphylococcus, catalase – Streptococcus

4. Gram negative unknown
Examine the isolated colonies on MacConkey and determine the color of the colony.
Pink – lactose fermenter
White/colorless – lactose nonfermenter
We do not need this information for gram positive.

5. Non- fermenter TSI slant – only one Urea broth Fermenter
Tryptone broth – 1
MRVP – 2
Citrate slant – 1
Urea broth – 1
Motility - 1

6. 3rd lab session
Match the results on your unknown with the results on the tables for the known bacteria.

7. Table 3
Table 1
Table 2
Table 4