Product number: 7221

SIM Medium is used for the differentiation of microorganisms on the basis of hydrogen sulfide production, indole production, and motility in a laboratory setting. SIM Medium is not intended for use in the diagnosis of disease or other conditions in humans.

Semisolid media have been used extensively in the determination of bacterial motility. The production of hydrogen sulfide, indole formation, and motility are useful diagnostic tests in the identification of Enterobacteriaceae, especially Salmonella spp. and Shigella spp.

In 1940, Sulkin and Willett demonstrated motility, hydrogen sulfide production, and carbohydrate fermentation by members of Salmonella and Shigella groups. They called attention to the "brush-like growth" or motility of the typhoid organisms. Greene et al. used SIM Medium to detect motility in a large series of cultures of typhoid organisms.


Formula Liter
Enzymatic Digest of Casein 20 g
Enzymatic Digest of Animal Tissue 6.1 g
Ferric Ammonium Citrate 0.2 g
Sodium Thiosulfate 0.2 g
Agar 3.5 g

Final pH: 7.3 ± 0.2 at 25°C
Formula may be adjusted and/or supplemented as required to meet performance specifications.


  1. Dissolve 30 g of the medium in one liter of purified water.
  2. Heat with frequent agitation to completely dissolve the medium.
  3. Autoclave at 121°C for 15 minutes.

Order Details

Product # Product Description
7221A SIM Medium, 500 g

Reference Material

NCM0277 - SIM Medium, Safety Data Sheet [Danish] [Dutch] [English] [EU English] [Finnish] [French] [German] [Hungarian] [Italian] [Spanish, Mexico] [Swedish]
NCM0277 - SIM Medium, Technical Specifications Sheet [English]
7221 - SIM Medium, Product Information Sheet [English]

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