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Endo Agar | Selective Medium for Coliform Detection | AS‑1219
$125.00 AUD
AuSaMicS Life Science • Culture Media
Endo Agar
Selective Differential Medium for Coliform Detection (Membrane Filtration Compatible)
Endo Agar is a selective and differential medium for the detection of coliform bacteria based on lactose fermentation. Lactose-positive organisms produce characteristic red colonies with a metallic sheen, making Endo Agar a classical and reliable medium for water quality testing and sanitary analysis, particularly in membrane filtration workflows.
AS-1219
Coliform Detection
✓ Lactose Differential
Metallic Sheen
💧 Water microbiology standard
🧫 Membrane filtration compatible
🧪 Selective inhibition of Gram-positive bacteria
🏆 Coliform Indicator Medium
🦠 E. coli → metallic sheen
⚗️ Lactose fermentation visible
📋 COA + SDS available
💧 Ideal for water testing labs
Key Reaction
Lactose → acid → aldehyde reaction → metallic sheen
🔬 Principle of the Medium
Endo Agar contains lactose as the fermentable carbohydrate and a combination of basic fuchsin and sodium sulfite as the indicator system. Acid production from lactose fermentation leads to color development, while strong fermenters such as Escherichia coli produce a distinctive green metallic sheen.
The medium is selective due to the inhibitory effect of basic fuchsin on Gram-positive organisms, enhancing recovery of Gram-negative enteric bacteria.
Lactose → Acid
↓
Fuchsin reaction → Red / Metallic colonies
↓
Fuchsin reaction → Red / Metallic colonies
🧪 Applications
- Detection of coliform bacteria in water
- Membrane filtration methods for potable water testing
- Sanitary analysis of food and environmental samples
- Differentiation of lactose fermenters vs non-fermenters
📊 Coliform Media Comparison
| Medium | Selectivity | Differentiation | Best Use |
|---|---|---|---|
| Endo Agar | Moderate | Metallic sheen | Water testing (MF) |
| MacConkey Agar | Moderate | Pink colonies | General clinical |
| EMB Agar | Moderate | Sheen (E. coli) | Enteric differentiation |
| M-Endo Agar LES | Optimized | Coliform sheen | Standard MF methods |
💡 Practical Notes
- Best used in membrane filtration workflows
- Strong lactose fermenters produce metallic sheen
- Non-fermenters remain colorless or pale
- Confirmatory testing recommended for final identification
📋 Technical Specifications
| Product Code | AS-1219 |
| Format | Dehydrated powder |
| Type | Selective differential agar |
| Key Components | Lactose, peptone, basic fuchsin, sodium sulfite, agar |
| Final pH | ~7.4 ± 0.2 |
| Storage | 15–25°C dry |
| HS Code | 3821.00.00 |
🧫 Interpretation
- ✓ Metallic sheen → E. coli (strong lactose fermenter)
- ✓ Red colonies → lactose positive
- ✓ Colorless → non-lactose fermenter
✅ Quality
- ✓ Consistent colony morphology
- ✓ Clear differentiation
- ✓ Batch-tested
Disclaimer: For laboratory and research use only.