Trypticasein Soy Broth Modified with Novobiocin (mTSB) is a selective enrichment broth used for the detection of Escherichia coli O157:H7 and other Shiga toxin-producing E. coli (STEC). This formulation is strictly compliant with the ISO 16654 standard, making it the primary choice for food safety laboratories testing meat, dairy, and environmental samples for these critical pathogens.
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1292 Trypticasein Soy Broth Modified with Novobiocin (mTSB) ISO, Condalab
1292
Condalab
The medium is an adaptation of the traditional Tryptic Soy Broth (TSB), modified to enhance the recovery of E. coli O157:H7 while suppressing competing microflora. The Tryptone and Soy Peptone provide a rich base of nitrogen, amino acids, and vitamins. Glucose serves as the energy source, and Sodium Chloride maintains osmotic balance. Dipotassium Phosphate acts as a buffer to prevent a rapid drop in pH due to fermentation. The key modifications include the addition of Bile Salts No. 3 to inhibit Gram-positive bacteria and the inclusion of Novobiocin. Novobiocin is a selective antibiotic that specifically inhibits the growth of Proteus species and other Gram-negative competitors, allowing E. coli O157:H7 to multiply to detectable levels during the enrichment phase.
Advantages
- ISO 16654 Compliance: Formulated specifically to meet international standards for the detection of Escherichia coli O157.
- High Specificity: The combination of Bile Salts and Novobiocin significantly reduces the background growth of non-target organisms.
- Optimized for STEC: Recognized as the standard enrichment medium for the recovery of Shiga toxin-producing E. coli from complex food matrices.
- Robust Buffering: Ensures that the pH remains within an optimal range for E. coli survival even during active carbohydrate metabolism.
- Reliable Quality: Essential for regulatory compliance in the testing of raw beef and other high-risk food products.
Instructions for use
Suspend 33.0 g of the powder in 1 liter of distilled or deionized water. Mix thoroughly until the powder is completely dissolved. Preparation: Sterilize by autoclaving at 121 °C for 15 minutes. Note: For the full selective medium as per ISO 16654, the Novobiocin is often included in the dehydrated base (as in this Cat. 1292) or may need to be added as a supplement depending on the specific application. Inoculate the sample (typically a 1:10 dilution) and incubate at 41.5 ± 1 °C for 6 to 24 hours. The elevated temperature is critical for the selective enrichment of E. coli O157.
Technical specifications
| Catalogue number | 1292 |
| Brand | Condalab |
| Application | Selective enrichment of E. coli O157:H7 (ISO 16654) |
| Typical Composition (g/L) | Tryptone (17.0); Soy Peptone (3.0); Sodium Chloride (5.0); Dipotassium Phosphate (2.5); Glucose (2.5); Bile Salts No. 3 (1.5); Novobiocin (0.02) |
| Final pH (at 25 °C) | 7.3 ± 0.2 |
| Preparation | 33.0 g/L |
| Storage Temperature | 2 – 25 °C |
Available packaging options
| 1292 | 500 g plastic bottle |
| Brand | Condalab |
| Pack size | 500 g |
