Unknowns

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

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

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.

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

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

Table 3 Table 1 Table 2 Table 4