Decarboxylase Broth Base, Moeller | Amino Acid Decarboxylation Medium | AS‑1193
Decarboxylase Broth Base, Moeller
Differential Medium for Amino Acid Decarboxylation Testing (Lysine, Ornithine, Arginine)
Moeller Decarboxylase Broth Base is a differential biochemical medium used for the detection of amino acid decarboxylation in microorganisms, particularly Enterobacteriaceae. When supplemented with specific amino acids (e.g., lysine, ornithine, arginine), it enables clear differentiation based on alkaline end-product formation.
🏆 Identification Medium
🔬 Principle of the Medium
The medium contains glucose and a pH indicator (bromocresol purple). Initially, glucose fermentation produces acid, lowering the pH and turning the medium yellow.
If the organism possesses the appropriate decarboxylase enzyme, it will convert the amino acid into alkaline amines, raising the pH and restoring the color to purple.
+ Decarboxylation → Alkaline amines (purple)
🧪 Applications
- Differentiation of Enterobacteriaceae
- Identification of Gram-negative rods in clinical microbiology
- Biochemical profiling in food and environmental microbiology
- Used in conjunction with lysine, ornithine, and arginine supplements
📊 Biochemical Media Comparison
| Medium | Test Type | Target Reaction | Use |
|---|---|---|---|
| Moeller Decarboxylase Broth | Decarboxylation | Amino acids → amines | Enterobacteriaceae ID |
| Urea Broth | Urease | Urea → ammonia | Proteus detection |
| TSI Agar | Fermentation | Sugar metabolism | Enteric screening |
| SIM Medium | Multi-test | H2S / indole / motility | Identification panel |
💡 Practical Notes
- Requires addition of specific amino acids before use
- Oil overlay recommended to ensure anaerobic conditions
- Interpretation based on color change (purple vs yellow)
- Must include control tube without amino acid
📋 Technical Specifications
| Product Code | AS-1193 |
| Format | Dehydrated powder |
| Type | Differential broth base |
| Indicator | Bromocresol purple |
| Key Components | Peptone, glucose, pyridoxal, indicator |
| Final pH | ~6.0–6.5 |
| Storage | 15–25°C dry |
| HS Code | 3821.00.00 |
🧫 Interpretation Guide
- 🟡 Yellow → Acid production only (negative)
- 🟣 Purple → Decarboxylation positive
- ⚪ No change → Inactive organism
✅ Quality
- ✓ Reliable biochemical differentiation
- ✓ Consistent indicator response
- ✓ COA available
Disclaimer: For laboratory and research use only.