Culture Media
Organism
Colony Morphology
EMB Agar Media
Escherichia coli
Yellow-greenish metallic sheen colonies.
Klebsiella spp.
Purple mucoid colonies.
Salmonella spp.
Colorless colonies.
McConkey Agar Plate Escherichia coli
Pink lactose fermenter colonies.
Klebsiella spp.
Pink mucoid lactose fermenter colonies.
Salmonella spp.
Colorless non-lactose fermenter colonies.
Escherichia coli
Yellow colonies due to low pH (acid produced during
lactose/sucrose fermentation).
Salmonella spp.
White colonies with red media, indicating no lactose/sucrose
fermentation.
Salmonella spp.
Black pigment colonies (H₂S production).
Klebsiella spp.
Pink mucoid colonies.
Chocolate Agar Plate
Haemophilus spp.
Large white mucoid colonies.
Blood Agar Plate
Streptococcus
pneumoniae
Alpha hemolysis (greenish zone of hemolysis).
Brilliant Green Agar
(BGA)
S–S Agar Plate
Streptococcus pyogenes Beta hemolysis (clear zone of hemolysis).
Mannitol Salt Agar
(MSA)
TCBS Agar Plate
Enterococcus faecalis
Gamma hemolysis (no detectable hemolysis).
Staphylococcus aureus
Yellow colonies with yellow zones.
Staphylococcus
epidermis
Small pink or red colonies with no color change in the
medium.
Vibrio cholerae
Yellow-stained colonies.
Vibrio parahaemolyticus Blue to green-centered colonies.
Lowenstein–Jensen
Medium
Mycobacterium
tuberculosis
Buff to yellow, rough, wrinkled colonies after 6 weeks at
37°C.