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  1. Laboratory Methods (Food)

BAM Media M145: Tetrathionate (TT) Broth

Media Index for BAM

March 2025

Tetrathionate broth base

Polypeptone5 g
Bile salts1 g
Calcium carbonate10 g
Sodium thiosulfate·5H2O30 g
Distilled water1 liter

Suspend ingredients in 1 liter distilled water, mix, and heat to boiling. DO NOT AUTOCLAVE. (Precipitate will not dissolve completely.) Cool to less than 45°C. Store at 5-8°C. Final pH, 8.4 ± 0.2.

Iodine-Potassium Iodide (I2-KI) solution

Potassium iodide5 g
Iodine, resublimed6 g
Distilled water, sterile20 mL

Dissolve potassium iodide in 5 ml sterile distilled water. Add iodine and stir to dissolve. Dilute to 20 ml.

Brilliant Green Solution (0.1%)

Brilliant green dye, sterile0.1 g
Distilled water, sterile100 mL

Dissolve 0.1 g brilliant green dye in 10 mL sterile distilled water. Dilute to 100 mL in sterile distilled water. On day of use, add 20 ml of I2-KI solution and 10 ml of brilliant green solution (0.1%) to 1 liter base. Resuspend precipitate by gentle agitation and aseptically dispense 10 ml portions into 20 × 150 or 16 × 150 mm sterile test tubes. Do not heat medium after addition of I2-KI and dye solutions.  

A second version of TT, Tetrathionate Broth Hajna (TTH), is utilized to detect Salmonella enterica Serovar Enteritidis in humans and animals, specifically to detect Salmonella in poultry houses.

Preparation of Medium:

Sodium Thiosulfate (Na2S2O3)

38.0 g

Calcium Carbonate (CaCO3)

25.0 g

Casein/meat peptone (50/50)

18.0 g

Sodium Chloride (NaCl)

5.0 g

D-Mannitol

2.5 g

Yeast extract

2.0 g

Glucose

0.5 g

Sodium deoxycholate

0.5 g

Brilliant green

0.01 g

Iodine-Potassium Iodide solution

                               KI           8g/L

                              Iodine     5 g/L

40.0 mL

  • Add components, except iodine solution, to distilled/deionized water
    and bring volume to 960 mL.
  • Mix thoroughly.
  • Gently heat and bring to boiling.
  • Do not autoclave. Cool to 40°C and then add 40 mL iodine solution.
  • Mix thoroughly and distribute into tubes in 10 mL volumes.
  • Final pH is 7.5 to 7.8. Use medium the same day as prepared.

Original Source: Bacteriological Analytical Manual, 8th Edition, Revision A, 1998.

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