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Letheen Agar | AS-1387 | Cosmetic Preservative Neutralizing Medium | AuSaMicS
$37.00 AUD
AuSaMicS Life Science • Neutralizing Agar for Disinfectant Residues
Letheen Agar
Letheen Agar is a neutralizing medium used for determination of bactericidal activity and for recovery of microorganisms from surfaces, utensils, equipment, and samples containing disinfectant residues. Lecithin neutralizes quaternary ammonium compounds, while polysorbate 80 neutralizes phenolics, hexachlorophene, and formalin residues.
Cat No.: AS-1387
Neutralizing AgarQuat / Phenolic ResiduesAustralian Stock
Format: Dehydrated culture medium SKU: To be assigned Support: COA / technical support available
Application Summary
Professional laboratory use
Reliable workflow integration
Australian stock
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Overview & Applications
Letheen Agar is a neutralizing medium used for determination of bactericidal activity and for recovery of microorganisms from surfaces, utensils, equipment, and samples containing disinfectant residues. Lecithin neutralizes quaternary ammonium compounds, while polysorbate 80 neutralizes phenolics, hexachlorophene, and formalin residues.
Primary Applications
- Disinfectant efficacy and neutralization studies
- Environmental monitoring and sanitation validation
- Recovery of microorganisms from sanitized surfaces
- Testing of cosmetics and manufacturing hygiene systems
Key Features
- Lecithin neutralizes quaternary ammonium compounds
- Polysorbate 80 neutralizes phenolic-type residues
- Supports recovery of stressed survivors after sanitizer exposure
- Suitable for sanitation and hygiene validation workflows
Typical Composition / Product Characteristics
| Component / Attribute | Amount / Value | Function | Practical Role |
|---|---|---|---|
| Casein enzymic hydrolysate | 5.0 g/L | Nutrient source | Provides peptides and amino acids |
| Beef extract | 3.0 g/L | Growth factors | Adds vitamins and trace nutrients |
| Dextrose | 1.0 g/L | Energy source | Supports recovery and growth |
| Polysorbate 80 | 5.0 g/L | Neutralizer | Neutralizes phenolics and related residues |
| Lecithin | 0.7 g/L | Neutralizer | Neutralizes quaternary ammonium compounds |
| Agar | 15.0 g/L | Solidifying agent | Forms plate or tube medium |
| Final pH | 7.0 ± 0.2 | Balanced growth condition | Supports recovery of exposed cells |
Preparation, Incubation & Interpretation
Preparation
Suspend 32 g in 1 L distilled or purified water. Heat to dissolve completely. Sterilize by autoclaving at 121°C for 15 minutes. Mix well and dispense into plates or tubes as required.
Incubation / Use
Incubation depends on the target organism and test method. Typical recovery studies are performed at 30–37°C for 24–48 hours.
Interpretation
Letheen Agar is not primarily differential. It is used to determine whether viable organisms can be recovered in the presence of neutralized disinfectant residues and to compare microbial survival or sanitation effectiveness.
Comparative Media / Workflow Position
| Medium / Product | Primary Target | Principle | Typical Use | Key Advantage |
|---|---|---|---|---|
| Letheen Agar | Disinfectant-exposed organisms | Neutralizer agar | Sanitation validation | Lecithin + polysorbate 80 neutralization |
| Tryptone Glucose Extract Agar | General bacteria | Nutrient agar | Routine cultivation | No disinfectant neutralization |
| D/E Neutralizing Agar | Broad disinfectant residues | Multi-neutralizer medium | Environmental monitoring | Wider neutralization spectrum |
| Plate Count Agar | Aerobic counts | Enumeration medium | Routine count work | Standard counting medium |
Recommended Workflow
1. Sample contact surface
Use swabs, rinses, or contact methods from sanitized equipment or surfaces.
Use swabs, rinses, or contact methods from sanitized equipment or surfaces.
2. Neutralize residues
Letheen Agar neutralizes specific sanitizer carryover to allow survivor recovery.
Letheen Agar neutralizes specific sanitizer carryover to allow survivor recovery.
3. Incubate
Use the method-appropriate organism and incubation conditions.
Use the method-appropriate organism and incubation conditions.
4. Assess recovery
Compare colony recovery to controls to evaluate sanitation effectiveness.
Compare colony recovery to controls to evaluate sanitation effectiveness.
Strategic Use
Advantages
- Excellent for quaternary ammonium and phenolic disinfectant recovery studies
- Supports stressed-cell recovery after sanitizer exposure
- Useful in environmental monitoring and hygiene validation
Considerations
- Not a broad-spectrum differential medium
- Neutralizer coverage is narrower than some multi-neutralizer media
- Method suitability depends on the disinfectant chemistry in use
Selection Guide
- Use for quat sanitizer validation and neutralization checks
- Choose when lecithin and polysorbate 80 are the appropriate neutralizer pair
- Good option for manufacturing, food, and cosmetics hygiene programs