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↓
+ β-gur component cleaved → blue-indigo component
↓
= Dark blue to violet colony
↓
β-gur component NOT cleaved (no β-gur enzyme)
↓
= Magenta to red colony
AuSaMicS ECC Agar — E. coli & Coliform Chromogenic Medium (AS-1438)
$145.00 AUD
Documentation
AuSaMicS ECC Agar — E. coli & Coliform Detection Medium
Simultaneous Detection and Differentiation of E. coli and Total Coliforms in a Single Plate | Dual Chromogenic Substrate System | Cat. No. AS-1438
Cat. No. AS-1438 pH 7.0 ± 0.2 ⚠ DO NOT AUTOCLAVE 🔵 E. coli → Blue-Violet 🟣 Coliforms → Magenta-Red ✓ ISO 11133 Performance Tested 🇦🇺 Made in Melbourne ⚡ Same-Week Dispatch
E. coli
Dark blue to violet
Total Coliforms
Magenta to red
Non-coliforms
Colourless / inhibited
Cat. No.
AS-1438
pH (25°C)
7.0 ± 0.2
Incubation
36±2°C / 21±3h
E. coli
Blue-Violet
Coliforms
Magenta-Red
📄 Full DocumentationCOA, TDS & SDS every batch
🇦🇺 Australian StockNo import delays
⚡ Same-Week DispatchMelbourne warehouse
🔬 Technical SupportDirect from our team
Overview
ECC Agar (AS-1438) is a selective and differential chromogenic culture medium for the simultaneous detection and enumeration of E. coli and total coliform bacteria from a single plate, without the need for confirmation steps. The medium uses a Chromogenic Substrate Complex targeting two bacterial enzymes to produce visually distinct colony colours that allow immediate differentiation.
ECC Agar is performance tested according to ISO 11133 and is widely used in water quality testing, food microbiology, environmental monitoring, and pharmaceutical QC laboratories across Australia and internationally.
The Chromogenic Substrate Complex — How It Works
Component 1 — β-D-galactosidase activity:
All coliform bacteria produce β-D-galactosidase, which cleaves this component of the complex to release a magenta/red chromophore. This produces magenta to red colonies for all coliforms, including E. coli.
Component 2 — β-D-glucuronidase activity:
E. coli specifically produces β-D-glucuronidase, which cleaves the second component of the complex to release a blue-indigo chromophore. When combined with the magenta colour from the first reaction, the result is dark blue to violet colonies — a visually unambiguous signal for E. coli.
Result by colony colour:
🔵 Blue-violet = E. coli (both enzymes present)
🟣 Magenta to red = other coliforms (β-gal only, no β-glucuronidase)
⚪ Colourless / no growth = non-coliforms (suppressed by sodium lauryl sulphate)
All coliform bacteria produce β-D-galactosidase, which cleaves this component of the complex to release a magenta/red chromophore. This produces magenta to red colonies for all coliforms, including E. coli.
Component 2 — β-D-glucuronidase activity:
E. coli specifically produces β-D-glucuronidase, which cleaves the second component of the complex to release a blue-indigo chromophore. When combined with the magenta colour from the first reaction, the result is dark blue to violet colonies — a visually unambiguous signal for E. coli.
Result by colony colour:
🔵 Blue-violet = E. coli (both enzymes present)
🟣 Magenta to red = other coliforms (β-gal only, no β-glucuronidase)
⚪ Colourless / no growth = non-coliforms (suppressed by sodium lauryl sulphate)
Colony Colour Guide
🔵 DARK BLUE TO VIOLET
E. coli
Dual enzyme activity
Count separately
Majority of E. coli strains
🟣 MAGENTA TO RED
Total coliforms (non-E. coli)
Single enzyme activity
Count separately
Klebsiella, Enterobacter, Citrobacter
⚪ COLOURLESS / NONE
Non-coliforms
Neither enzyme present
Suppressed or no colour
Do not count
How to count and report:
E. coli count = number of dark blue to violet colonies on the membrane.
Total coliform count = blue-violet colonies + magenta/red colonies (sum of both colour groups).
Report as CFU per 100 mL of sample volume filtered.
E. coli count = number of dark blue to violet colonies on the membrane.
Total coliform count = blue-violet colonies + magenta/red colonies (sum of both colour groups).
Report as CFU per 100 mL of sample volume filtered.
⚠️ Aeromonas spp. false positives: Some Aeromonas species are oxidase-positive but may produce β-glucuronidase, generating blue-violet colonies on ECC Agar. Perform an oxidase test on suspect colonies when Aeromonas is a concern (environmental and surface water samples). Oxidase-positive blue-violet colonies should not be counted as E. coli.
Detection Pathways
🔵 E. coli Detection Pathway
β-gal component cleaved → magenta component↓
+ β-gur component cleaved → blue-indigo component
↓
= Dark blue to violet colony
🟣 Other Coliform Detection Pathway
β-gal component cleaved → magenta component↓
β-gur component NOT cleaved (no β-gur enzyme)
↓
= Magenta to red colony
Applications
💧
Drinking Water
Membrane filtration, 100 mL sample
🏊
Recreational Water
Bathing water, pools, beach water compliance
🌊
Environmental Water
Rivers, lakes, stormwater, irrigation water
🍕
Food & Dairy
Process water, hygiene monitoring, product testing
💊
Pharmaceutical QC
Process water testing for coliforms
🏭
Environmental Monitoring
Surface sampling, wastewater, effluent compliance
Performance Testing
ISO 11133Microbiology of food, animal feed and water — Preparation, production, storage and performance testing of culture media
ISO 7218:2007Microbiology of food — General requirements for microbiological examinations
ECC Agar vs Other E. coli / Coliform Detection Media
| Medium | E. coli | Total Coliforms | Temp | Testing |
|---|---|---|---|---|
| ECC Agar (AS-1438) ★ | 🔵 Blue-violet | 🟣 Magenta-red | 36±2°C | ISO 11133 performance tested |
| TBX Agar | 🟢 Blue-green (β-gur only) | No differentiation | 44°C | ISO 16649-2 |
| m-FC Agar (AS-1405) | 🔵 Blue (all thermotolerant) | No differentiation | 44.5°C | APHA 9222D |
| m-Endo Agar | Part of total coliforms | 🔴 Red + metallic sheen | 35°C | APHA 9222B |
FAQs
❓ Can I detect both E. coli and total coliforms from a single plate?
Yes — this is the key advantage of ECC Agar. A single plate after 21 ± 3 hours incubation gives you: (1) the E. coli count directly from blue-violet colonies, and (2) the total coliform count from the sum of all blue-violet + magenta/red colonies. No separate plates or confirmation steps are required for routine testing.
❓ What about E. coli strains that are β-glucuronidase negative?
Approximately 96–97% of E. coli strains are β-D-glucuronidase positive and produce the characteristic blue-violet colour on ECC Agar. The remaining 3–4% are β-glucuronidase negative — most notably many E. coli O157:H7 strains — and will appear magenta-pink instead (counted as coliforms, not E. coli). For food safety testing specifically targeting O157:H7, a dedicated medium is required.
❓ Why must ECC Agar NOT be autoclaved?
The Chromogenic Substrate Complex is heat-sensitive. Autoclaving at 121°C degrades these compounds, eliminating the colour development that is the medium's primary detection mechanism. The correct preparation is: dissolve by heating to boiling with agitation for approximately 1 minute, then cool to 45–50°C before pouring. Do not over-boil.
❓ What is sodium lauryl sulphate and why is it in this medium?
Sodium lauryl sulphate (0.2 g/L) is the primary selective agent in ECC Agar. It inhibits the growth of Gram-positive organisms without significantly affecting the growth of the target coliforms and E. coli, helping to provide clean, readable colony differentiation on mixed-flora samples.
❓ What incubation temperature is recommended?
36 ± 2°C for 21 ± 3 hours. Verify your incubator calibration before routine use.
Related Products
Product Specifications
| Product Name | ECC Agar — E. coli & Coliform Chromogenic Agar |
| Catalogue Number | AS-1438 |
| Synonyms | ECC Agar; E. coli Coliform Detection Medium |
| Performance Testing | ISO 11133 |
| Medium Type | Selective differential chromogenic agar — dual enzyme substrate system |
| Final pH at 25°C | 7.0 ± 0.2 |
| Sterilisation | DO NOT AUTOCLAVE — heat to boiling to dissolve (~1 minute), then cool to 45–50°C |
| Appearance (powder) | Beige to light tan, free-flowing homogeneous powder |
| Appearance (prepared) | Light amber to pale yellow, slightly opalescent gel |
| Incubation | 36 ± 2°C for 21 ± 3 hours — aerobically |
| Storage (powder) | 2–25°C, dry, protected from moisture and direct light |
| Storage (prepared plates) | 2–8°C; use within 2 weeks. Protect from light. |
| Suspension Rate | 39.3 g/L — yields approx. 2.5 L of prepared medium per 100 g pack |
| HS Tariff Code | 3821.00.00 |
Formula — Per Litre
| Ingredient | g / L | Role |
|---|---|---|
| Peptone | 10.0 | Primary nitrogen — amino acids, peptides, growth factors |
| D-Sorbitol | 1.0 | Carbohydrate; supports coliform growth and recovery |
| Sodium Chloride | 5.0 | Osmotic balance |
| Dipotassium Hydrogen Phosphate (K₂HPO₄) | 2.7 | pH buffer component |
| Potassium Dihydrogen Phosphate (KH₂PO₄) | 2.2 | pH buffer component |
| Sodium Pyruvate | 1.0 | Energy source; supports recovery of stressed/injured coliform cells |
| L-Tryptophan | 1.0 | Supports indole reaction; improves detection reliability |
| Potassium Nitrate | 1.0 | Supplementary selective / growth-support agent |
| Chromogenic Substrate Complex | 0.2 | Dual chromogenic system — coliforms → magenta-red colonies; E. coli → dark blue-violet colonies |
| Sodium Lauryl Sulphate | 0.2 | Primary selective agent — suppresses Gram-positive organisms without affecting coliforms |
| Agar | 15.0 | Solidifying agent |
| Total dissolution | 39.3 g/L | pH 7.0 ± 0.2 at 25°C | DO NOT AUTOCLAVE — heat to boiling to dissolve | Cool to 45–50°C before pouring |
Preparation Protocol
⚠️ DO NOT AUTOCLAVE. The Chromogenic Substrate Complex is degraded by autoclaving. Use boiling water bath or direct heat only.
1
Suspend 39.3 g of dehydrated ECC Agar (AS-1438) per litre of purified or distilled water. Allow to stand a few minutes to hydrate.
2
Heat with frequent agitation to boiling. Boil for approximately 1 minute to dissolve completely. Avoid prolonged boiling.
3
Cool to 45–50°C in a water bath. Do not allow to set — pour while still molten.
4
Pour 15–20 mL per 90 mm Petri dish. Allow to solidify on a level surface.
5
Dry the agar surface — leave lids ajar at room temperature for 30–60 minutes, or dry at 37°C for 30 min. Surface moisture causes colony spreading.
6
For membrane filtration (water testing): place membrane filter grid-side up on ECC Agar. Incubate at 36 ± 2°C for 21 ± 3 hours. Count blue-violet (E. coli) and magenta-red (coliforms) colonies separately.
QC Organisms & Expected Results
| Organism (ATCC) | Expected Growth | Colony Colour | Interpretation |
|---|---|---|---|
| Escherichia coli ATCC 25922 | Good growth; ≤100 CFU | Dark blue to violet | E. coli ✓ |
| Escherichia coli ATCC 8739 | Good growth; ≤100 CFU | Dark blue to violet | E. coli ✓ |
| Enterobacter aerogenes / Klebsiella aerogenes ATCC 13048 | Good growth; ≤100 CFU | Magenta to red | Coliform (non-E. coli) ✓ |
| Citrobacter freundii ATCC 43864 | Good growth | Magenta to red | Coliform ✓ |
| Enterococcus faecalis ATCC 19433 | Inhibited / partial growth | No colour | Non-coliform — inhibited ✓ |
| Staphylococcus aureus ATCC 25923 | Inhibited / no growth | No colour | Non-coliform — inhibited ✓ |
Literature & References
| # | Reference |
|---|---|
| 1 | Farnleitner AH, et al. Performance validation of chromogenic coliform agar for the enumeration of E. coli and coliform bacteria. J Appl Microbiol. 2004. |
| 2 | Manafi M, Kneifel W. A combined chromogenic-fluorogenic medium for the simultaneous detection of total coliforms and E. coli in water. Zentralbl Hyg Umweltmed. 1990;189:225–234. |
| 3 | ISO 7218:2007. Microbiology of food and animal feeding stuffs — General requirements and guidance for microbiological examinations. Geneva: ISO; 2007. |
| 4 | ISO 11133:2014. Performance testing of culture media. Geneva: ISO; 2014. |
📄 Full 16-section GHS SDS available (Australian WHS Regulations 2023 / GHS 7th Edition) — support@ausamics.com.au
Section 1 — Identification
| Product Name | ECC Agar — E. coli & Coliform Chromogenic Agar |
| Catalogue No. | AS-1438 |
| Intended Use | Selective differential chromogenic culture medium for detection and enumeration of E. coli and total coliforms. Laboratory use only. |
| Supplier | AuSaMicS Pty Ltd | ABN 56 676 640 467 |
| Address | 36/25 Trafalgar Road, Epping, VIC 3076, Australia |
| Emergency | Poisons Information Centre: 13 11 26 (24 hr) |
| Phone | +61 412 520 598 | support@ausamics.com.au |
Section 2 — Hazard Identification (GHS 7th Ed / WHS 2023)
| GHS Classification | NOT classified as a hazardous substance under Australian WHS Regulations 2023 at intended use concentrations. GHS07 (irritant) may apply for dust exposure during bulk weighing — apply precautionary handling. |
| Signal Word | Warning (dust inhalation precautionary only) |
| Hazard Statement | H335 — may cause respiratory irritation (precautionary; bulk powder handling) |
| Other Hazards | Combustible powder. Chromogenic Substrate Complex at 0.2 g/L: not classified hazardous. Sodium lauryl sulphate at 0.2 g/L: mild irritant at use level. |
Composition
| Component | g/L | CAS | Hazard |
|---|---|---|---|
| Peptone | 10.0 | 73049-73-7 | Not hazardous |
| D-Sorbitol | 1.0 | 50-70-4 | Not hazardous |
| Sodium Chloride | 5.0 | 7647-14-5 | Not hazardous at use level |
| Phosphate buffer salts | 4.9 | 7758-11-4 / 7778-77-0 | Not hazardous at use level |
| Sodium Pyruvate | 1.0 | 113-24-6 | Not hazardous |
| L-Tryptophan | 1.0 | 73-22-3 | Not hazardous |
| Potassium Nitrate | 1.0 | 7757-79-1 | Oxidiser — not classified at this use concentration |
| Chromogenic Substrate Complex (proprietary blend) | 0.2 | Mixture | Not classified hazardous at use concentration |
| Sodium Lauryl Sulphate | 0.2 | 151-21-3 | Mild irritant at high concentrations; not significant at 0.2 g/L |
| Agar | 15.0 | 9002-18-0 | Not hazardous |
| PPE | P1/P2 respirator when weighing bulk powder; safety glasses; nitrile gloves; lab coat |
| Waste | Autoclave 121°C / 15 min before disposal as microbiological waste |
| Storage | Store dry, cool (2–25°C), protected from direct sunlight and moisture |
| Transport | Not dangerous goods — ADG, IMDG, IATA |
Quality Specifications
| Parameter | Specification | Method |
|---|---|---|
| Appearance (powder) | Beige to light tan, free-flowing, homogeneous powder | Visual |
| Appearance (prepared) | Light amber, slightly opalescent; firm agar gel | Visual after dissolution |
| pH (prepared, 25°C) | 7.0 ± 0.2 | pH meter (calibrated) |
| Moisture Content | ≤8.0% (w/w) | Loss on drying |
| Growth — E. coli ATCC 25922 | Good growth; dark blue to violet; 36°C; 21–24h; ≤100 CFU | ISO 11133 |
| Growth — E. coli ATCC 8739 | Good growth; dark blue to violet; 36°C; 21–24h | ISO 11133 |
| Growth — K. aerogenes ATCC 13048 | Good growth; magenta to red; 36°C; 21–24h; ≤100 CFU | ISO 11133 |
| Inhibition — E. faecalis ATCC 19433 | Inhibited / no typical colour; ≤100 CFU inoculum | Selectivity check |
| Inhibition — S. aureus ATCC 25923 | Inhibited / no typical colour | Selectivity check |
| Recovery | ≥70% vs reference medium (TSA) | ISO 11133 |
| Batch COA | Available every production lot | Included with every order |
Pack Sizes
| 100 g | Method validation, small laboratory |
| 500 g | Routine water testing laboratory — most popular |
| 1 kg | High-throughput testing laboratory |
| 5 kg, 10 kg, 25 kg | Large facility, bulk procurement, government contract |
| Custom | Contact support@ausamics.com.au for institutional/tender quantities |
Manufacturing & Documentation
Manufactured by AuSaMicS Pty Ltd
36/25 Trafalgar Road, Epping, VIC 3076, Australia | ABN 56 676 640 467
✓ Formulated to a verified reference composition, performance tested per ISO 11133
✓ Chromogenic Substrate Complex: coliforms → magenta-red colonies; E. coli → dark blue-violet colonies
✓ Batch QC per ISO 11133 — pH, growth promotion, inhibition, colony colour
✓ COA, TDS, SDS included with every order
✓ Australian stock — same-week dispatch, no import delays
✓ Incubation: 36 ± 2°C / 21 ± 3h
36/25 Trafalgar Road, Epping, VIC 3076, Australia | ABN 56 676 640 467
✓ Formulated to a verified reference composition, performance tested per ISO 11133
✓ Chromogenic Substrate Complex: coliforms → magenta-red colonies; E. coli → dark blue-violet colonies
✓ Batch QC per ISO 11133 — pH, growth promotion, inhibition, colony colour
✓ COA, TDS, SDS included with every order
✓ Australian stock — same-week dispatch, no import delays
✓ Incubation: 36 ± 2°C / 21 ± 3h
⚠️ For laboratory, water quality testing, food microbiology, environmental testing, and research use only. Not for food, therapeutic, veterinary, or direct human use. Autoclave all inoculated material before disposal.