1. Motility test Bactria: Medium Escherichia coli Staphylococcus aureus
SIM (2)

2. SIM usage
Hydrogen sulfide production, indole formation and motility are distinguishing characteristics which aid in the identification of the Enterobacteriaceae.

3. Approximate Formula* Per Liter
Pancreatic Digest of Casein g
Peptic Digest of Animal Tissue … g
Ferrous Ammonium Sulfate g
Sodium Thiosulfate g
Agar g
Low agar percentage make this medium soft and let motile bacteria enable to diffuse (swim).

4. Sodium thiosulfate and ferrous ammonium sulfate are indicators of hydrogen sulfide production. The ferrous ammonium sulfate reacts with H2S gas to produce ferrous sulfide, a black precipitate (typical characteristics of Salmonella). The casein peptone is rich in tryptophan, which is attacked by certain microorganisms resulting in the production of indole.

5. Procedure Stab (about 1 cm) into SIM medium
Incubate at 37℃ for 24 hours