Pfizer Selective Enterococcus Agar (AS-1312)
$45.00 AUD
AuSaMicS Life Science • Selective Enterococcus Media
Pfizer Selective Enterococcus Agar
Historical High-Selectivity Enterococcus Isolation Medium
Classic highly selective agar developed for isolation of faecal enterococci from clinical, food, and water samples. The combination of sodium azide, thallous acetate, crystal violet, and esculin-ferric citrate creates a strongly selective system in which enterococci produce characteristic black halos by esculin hydrolysis.
AS-1312
🧪 Highly Selective Medium
✓ Historical Reference
⚠ Toxic Components
Target: Enterococcus spp.
Readout: Black halo from esculin hydrolysis
Status: Historical / reference use
Reference Media Specialist
Extreme Selectivity - Azide + thallous acetate
Clear Identification - Esculin black halo reaction
Historic Methodology - Classical enterococci isolation
Reference Use - Legacy methods and comparison studies
Technical Handling - Controlled laboratory use only
Legacy High-Selectivity Formula
Largely replaced by safer modern media
🧪 Complete Formulation & Selectivity Profile
📋 Original Pfizer-Type Composition (per Liter)
Final pH: 7.2 ± 0.2 at 25°C
⚗️ Functional Design
Extreme Selectivity
Azide and thallous acetate heavily suppress competing organisms
Azide and thallous acetate heavily suppress competing organisms
Differential Readout
Esculin hydrolysis produces distinctive black halo reactions
Esculin hydrolysis produces distinctive black halo reactions
Historical Specificity
Legacy medium for classical enterococcus isolation workflows
Legacy medium for classical enterococcus isolation workflows
Important: This medium contains highly toxic selective agents and is generally retained for historical, legacy, or reference purposes rather than routine modern laboratory use.
Complete Enterococcus Isolation Media Portfolio
Strategic Medium Selection for Enterococcus Isolation
✅ Pfizer Medium Advantages
- ✓ Exceptional Selectivity: Strong inhibition of non-target flora
- ✓ Clear Differential Reaction: Black halo around enterococci
- ✓ Historical Significance: Benchmark predecessor of later enterococcus media
- ✓ Reference Utility: Useful in legacy comparison work
⚠️ Method Considerations
- ▲ Contains Thallium Salts: Highly toxic, tightly controlled handling required
- ▲ Contains Sodium Azide: Toxic and hazardous waste considerations apply
- ▲ Shorter Plate Stability: Prepared plates should be used promptly
- ▲ Obsolete for Routine Use: Safer modern media are generally preferred
🎯 Best-Fit Applications
- ◆ Historical Method Comparison: Legacy method reconstruction
- ◆ Reference Laboratories: Classical enterococcus isolation studies
- ◆ Teaching Collections: Demonstration of legacy selective media
- ◆ Archive Protocol Support: Older regulatory or manual comparisons
📊 Colony Interpretation Guide
🔬 Quality Control & Performance Guidance
Typical Target:
Enterococcus faecalis
Enterococcus faecium
Enterococcus faecalis
Enterococcus faecium
Incubation:
35–37°C
24–48 hours
35–37°C
24–48 hours
Expected Reaction:
Grey-white colonies
Jet-black halo formation
Grey-white colonies
Jet-black halo formation
Handling Note:
Selective supplements added after sterilization
Use controlled hazardous-lab procedures
Selective supplements added after sterilization
Use controlled hazardous-lab procedures
Positioning: Historical and reference-use enterococcus isolation medium, largely replaced in routine laboratories by safer alternatives such as Slanetz-Bartley, KAA, and Bile Esculin Azide media.
📋 Technical Specifications
| Catalogue Number | AS-1312 |
| Medium Type | Highly selective differential agar |
| Target Organism | Enterococcus spp. |
| Final pH | 7.2 ± 0.2 (at 25°C) |
| Readout | Black halo from esculin hydrolysis |
| Sterilization | Base autoclaved; selective toxic supplements added after cooling |
| Prepared Plate Storage | 2–8°C, protected from light |
| Recommended Use Time | Within 1 week |
| Status | Historical / reference use only |
🧫 Primary Applications
- ✓ Isolation of enterococci from urine, wounds, faeces, food, and water
- ✓ Historical food and dairy testing workflows
- ✓ Reference laboratory comparisons against legacy methods
- ✓ Archive or retrospective protocol reconstruction
⚗️ Preparation Protocol
- 1. Suspend all base components except sodium azide and thallous acetate in approximately 900 mL purified water.
- 2. Heat and boil until fully dissolved.
- 3. Adjust pH, make up to 1 L, and autoclave the base.
- 4. Cool to about 50°C and add filter-sterilized sodium azide and thallous acetate solutions.
- 5. Mix carefully and pour plates under controlled hazardous-material handling conditions.
📦 Storage & Safety
Incubation: 35–37°C for 24–48 hours.
Plate storage: Store prepared plates at 2–8°C, protected from light, and use promptly.
Colony appearance: Typical enterococci appear grey-white with a jet-black halo.
Safety note: Contains thallium salts and sodium azide. Highly toxic and environmentally hazardous.
Laboratory notice: For historical and reference use only. Disposal must follow strict hazardous waste regulations.
AuSaMicS Life Science: Professional microbiology media for research, quality control, industrial, food, pharmaceutical, environmental, and reference laboratories. Product information is provided for laboratory and technical evaluation purposes only.