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DEV Tryptophan Broth (AS-1198)
$115.00 AUD
AuSaMicS Life Science • Water Analysis Standard
DEV Tryptophan Broth
Definitive Indole Test for E. coli Identification
A specialized tryptophan-rich medium designed according to DEV standards for the confirmation of Escherichia coli. Optimized for the performance of the Indole Test in the microbiological examination of water.
AS-1198
🧪 DEV Standard Compliant
✓ Indole Positive Control
💧 Water Quality
Test: Indole Production Incubation: 44°C / 21h Prep: 16.0g/L Yield
Identification Specialist
High Tryptophan - Maximum substrate availability
Clear Results - Minimal background interference
Regulatory Alignment - Meets German DEV criteria
Rapid Turnaround - Optimized for 21-hour protocols
Pure Amino Acid Base
Certified for Coliform Testing
🧪 Formulation & Reaction Principle
📋 Formulation (per Liter)
| Component | Concentration | Role |
|---|---|---|
| Peptone (Casein Hydrolysate) | 10.0 g | Rich source of L-Tryptophan |
| DL-Tryptophan | 1.0 g | Added substrate for Indole production |
| Sodium Chloride | 5.0 g | Osmotic stability |
Indole Reaction Interpretation
Positive Result (E. coli)
Addition of Kovac's Reagent produces a dark red/violet ring at the surface, indicating tryptophanase activity.
Negative Result
Reagent layer remains yellow or colorless, indicating no indole production (e.g., Enterobacter aerogenes).
📋 Technical Profile
| Catalogue No. | AS-1198 |
| Final pH | 7.2 ± 0.2 |
| Preparation | 16.0g per Liter |
| Appearance | Light yellowish powder |
⚗️ Laboratory Prep
- 1 Suspend 16.0g in 1L deionized water.
- 2 Dissolve completely and dispense into tubes.
- 3 Autoclave at 121°C for 15 min.