Overview & Scientific Background
TAT Broth — Tryptone-Azolectin-Tween Broth Base is the reference neutralising enrichment and diluent medium for microbiological examination of cosmetics, topical pharmaceuticals, and preservative-containing samples. It is widely known as TAT Broth (Tryptone-Azolectin-Tween), originally developed by the US FDA, and is validated under ISO 21149, ISO 18415, and ISO 16212.
Unlike SCDLP80 which uses Polysorbate 80, this medium uses Polysorbate 20 (Tween 20) at a high concentration (40 mL/L) and is specifically validated for viscous or gelatinous cosmetic samples (creams, ointments, lotions) where Polysorbate 20's superior emulsification properties aid sample dispersion and preservative neutralisation.
Mode of Action — Dual Neutralisation
Lecithin → QAC & Cationic Biocide Inactivation | Polysorbate 20 → Phenolic & Paraben Neutralisation
Soya Lecithin (5.0 g/L): Phospholipid that inactivates cationic antimicrobials — cetrimide, benzalkonium chloride, chlorhexidine, desqualinium acetate, and polymyxin B — by electrostatic binding of the negatively charged phosphate groups to the positively charged biocide molecules.
Polysorbate 20 / Tween 20 (40 mL/L): Non-ionic surfactant that forms micelles encapsulating and neutralising phenols, cresols, chlorocresol, benzoic acid, p-hydroxybenzoic acid and its esters (parabens). The synergistic combination of lecithin + Polysorbate 20 also inactivates ethanol and many quaternary ammonium/phosphonium compounds that neither agent alone fully neutralises.
High casein peptone (20 g/L) provides optimal conditions for spore germination and recovery of sublethally injured organisms — a critical requirement for cosmetics testing where preservatives cause sub-lethal stress rather than outright killing.
Applications
🧜
Cosmetics QC
Creams, lotions, ointments
💊
Topical Pharma
Salves, gels, eye drops
🏭
Viscous Samples
Emulsions & gelatinous materials
📊
Microbial Counts
USP <61>/<62> enumeration
🌿
Environmental
Swab & rinse sampling
🏫
Research
Preservative challenge studies
SCDLP20 vs SCDLP80 — Which Should You Use?
| Factor |
SCDLP20 / TAT Broth (AS-1357) |
SCDLP80 (AS-1351) |
| Polysorbate type |
Polysorbate 20 (Tween 20) — 40 mL/L |
Polysorbate 80 (Tween 80) — 5 g/L |
| Peptone base |
Casein peptone only (20 g/L) |
Casein (17g) + Soy (3g) peptone |
| Primary ISO reference |
ISO 21149 / ISO 16212 / USP <61> |
ISO 21149 / ISO 21150 / JP cosmetics |
| Viscous samples |
Preferred — Tween 20 superior emulsifier |
Good |
| Fatty/oily samples |
Good |
Better — Tween 80 more lipophilic |
| Paraben neutralisation |
✓ Excellent (Tween 20) |
✓ Good (Tween 80) |
| Equivalent products |
Merck 111723, BD Difco 298410, Sigma 22089 |
Oxoid CM0693, Merck 115923 |
ⓘ Quick guide: Use SCDLP20/TAT Broth for creams, ointments, gels, and gelatinous cosmetics. Use SCDLP80 when your method specifically references the JP/SCDLP80 formula or when testing fatty/oily products. Both are ISO 21149 compatible.
Cross-Reference / Equivalent Products
| Manufacturer |
Product Name |
Cat. No. |
Notes |
| Merck Millipore |
Casein Digest Soy Lecithin Polysorbate 20 (FCDLP 20) Broth Base |
111723 |
Reference standard — equivalent formula |
| BD Difco / Acumedia |
TAT Broth |
298410 / 7219 |
Equivalent formulation |
| Sigma-Aldrich |
TAT Broth (Casein-peptone Lecithin Polysorbate) |
22089 |
Equivalent formula |
| Liofilchem |
SCDLP 20 Broth ISO |
610148 |
Equivalent; ISO 21149 validated |
AuSaMicS AS-1357 is manufactured locally in Melbourne — same-week dispatch, no import delays.
Related Products
Product Identification
| Product Name |
TAT Broth — Tryptone-Azolectin-Tween Broth Base |
| Common Name |
TAT Broth (Tryptone-Azolectin-Tween Broth) |
| Synonyms |
Tryptone-Azolectin-Tween (TAT) Broth; Casein-Peptone Lecithin Polysorbate Broth Base; FCDLP20 Broth; Fluid Casein Digest-Soy Lecithin Polysorbate 20 Medium; SCDLP20 Broth |
| Catalogue Number |
AS-1352 |
| Medium Type |
Non-selective neutralising enrichment broth and sample diluent |
| Dissolution |
~65 g/L (add 40 mL Polysorbate 20 per litre after dissolving base) |
| Final pH at 25°C |
7.2 ± 0.2 |
| Sterilisation |
Autoclave 121°C for 15 minutes |
| Prepared Appearance |
Clear to slightly opalescent, light amber; slight turbidity from lecithin is normal |
| Dehydrated Appearance |
Light beige to beige free-flowing powder (Polysorbate 20 added separately as liquid) |
Formula — Per Litre (TAT Broth / FCDLP20 Standard)
✓ Verified formula. Reference: Merck Millipore Cat. 111723; BD Difco TAT Broth 298410; Sigma 22089. Note: Polysorbate 20 is added as a liquid (40 mL/L) after dissolving the base powder. Do NOT include Polysorbate 20 in the dehydrated powder calculation.
| Component |
Amount / L |
Role |
| Casein Peptone (Tryptone) |
20.0 g |
High-nitrogen source; spore germination & injured cell recovery support |
| Soya Lecithin |
5.0 g |
QAC neutraliser — inactivates cetrimide, chlorhexidine, benzalkonium chloride, polymyxin B |
| Polysorbate 20 (Tween® 20) |
40.0 mL |
Phenolic & paraben neutraliser; synergistic with lecithin for QAC/ethanol inactivation; emulsification of viscous samples |
| Total (base powder) |
25.0 g/L dry + 40 mL Polysorbate 20 |
Final pH 7.2 ± 0.2 at 25°C |
⚠️ Important preparation note: The dehydrated base contains casein peptone and soya lecithin. Polysorbate 20 must be added separately as 40 mL of liquid per litre after dissolving the base. Do not autoclave Polysorbate 20 alone; add to the base before or after autoclaving per your validated SOP.
Preparation Protocol
| 1 |
Dissolve 25 g of dehydrated base in approximately 950 mL of distilled or purified water with heating and stirring. |
| 2 |
Add 40 mL Polysorbate 20 (Tween 20). Mix until homogeneous. Adjust to final volume of 1 litre. |
| 3 |
Adjust pH to 7.2 ± 0.2 if required. |
| 4 |
Dispense into bottles or tubes. Autoclave at 121°C for 15 minutes. |
| 5 |
Cool and store at 2–8°C. Use within 4 weeks. Prepared broth should appear slightly opalescent — this is normal. |
| 6 |
For viscous samples: Add 1 g (or 1 mL) sample to 9 mL broth (1:10 dilution). Vortex or incubate at 30–35°C for 30 min with agitation to disperse sample before plating. |
Quality Control — Performance Organisms
| Organism (ATCC) |
Inoculum (CFU) |
Incubation |
Recovery |
|
Staphylococcus aureus (6538) |
≤100 |
30–35°C / 48–72h |
Good |
|
Pseudomonas aeruginosa (9027) |
≤100 |
30–35°C / 48–72h |
Good |
|
Escherichia coli (8739) |
≤100 |
30–35°C / 48–72h |
Good |
|
Candida albicans (10231) |
≤100 |
20–25°C / 5–7 days |
Good |
|
Aspergillus brasiliensis (16404) |
≤100 |
20–25°C / 5–7 days |
Good |
Regulatory Standards
| ISO 21149:2017 |
Cosmetics — Enumeration and detection of aerobic mesophilic bacteria |
| ISO 18415:2017 |
Cosmetics — Detection of specified and non-specified microorganisms |
| ISO 16212:2017 |
Cosmetics — Enumeration of yeast and mould |
| USP <61> / <62> |
Microbial examination of non-sterile products |
| EP 2.6.12 / 2.6.13 |
Microbiological examination of non-sterile products |
Literature & References
| # |
Reference |
| 1 |
Merck Millipore. Technical Data Sheet: Casein Digest Soy Lecithin Polysorbate 20 (FCDLP 20) Broth Base. Cat. 111723. Darmstadt: Merck; 2023. [Reference standard composition] |
| 2 |
ISO 21149:2017. Cosmetics — Microbiology — Enumeration and detection of aerobic mesophilic bacteria. Geneva: ISO; 2017. |
| 3 |
US Food and Drug Administration. Bacteriological Analytical Manual (BAM). Chapter 23: Examination of Cosmetics. FDA; updated 2023. |
| 4 |
ISO 18415:2017. Cosmetics — Microbiology — Detection of specified and non-specified microorganisms. Geneva: ISO; 2017. |
| 5 |
Cosmetic, Toiletry and Fragrance Association (CTFA). Microbiology Guidelines. 2020. [TAT Broth for cosmetics sterility testing] |
Storage
| Dehydrated Powder |
15–30°C, tightly sealed, away from moisture and light |
| Polysorbate 20 (liquid) |
Room temperature, tightly sealed. Avoid repeated freeze-thaw. |
| Prepared Broth |
2–8°C; use within 4 weeks |
📄
Full SDS available: 16-section GHS SDS (Australian WHS Regulations 2023 / GHS 7th Edition) —
support@ausamics.com.au
Section 1 — Identification
| Product Name |
TAT Broth — Tryptone-Azolectin-Tween Broth Base |
| Catalogue No. |
AS-1352 |
| Supplier |
AuSaMicS Pty Ltd | ABN 56 676 640 467 |
| Address |
31 Longview CT, Thomastown VIC 3074, Australia |
| Emergency |
Poisons Information Centre: 13 11 26 (24 hr) |
| Phone |
+61 412 520 598 |
| Email |
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. |
| Signal Word |
None required |
| Note on Polysorbate 20 |
Polysorbate 20 (Tween 20) may cause mild eye irritation at concentrated levels. At prepared medium concentrations (~4% v/v), not classified as hazardous. |
Sections 4–8 — First Aid & PPE
| Inhalation |
Remove to fresh air. Seek medical advice if symptoms persist. |
| Skin Contact |
Wash with soap and water. No significant hazard expected. |
| Eye Contact |
Irrigate with water ≥15 min. Seek medical attention if irritation persists (Polysorbate 20 content). |
| Ingestion |
Rinse mouth. Not acutely toxic. Call Poisons Centre 13 11 26 if large amounts ingested. |
| PPE |
Nitrile gloves, safety glasses, lab coat when handling prepared medium and inoculated cultures. |
| Biosafety |
Treat all inoculated media as potentially infectious. Autoclave (121°C / 15 min) before disposal. |
Sections 13–15 — Disposal & Regulatory
| Disposal |
Autoclave all inoculated broth before disposal as biological waste per institutional biosafety procedures. |
| Transport |
Not classified as dangerous goods — ADG, IMDG, IATA |
| Regulatory |
Australian WHS Regulations 2023 | GHS 7th Edition | Safe Work Australia COP 2021 |
| AICIS |
All components listed on AIIC or exempt |
Quality Specifications
| Parameter |
Specification |
Method |
| Appearance (powder) |
Light beige to beige free-flowing powder |
Visual |
| Appearance (prepared) |
Slightly opalescent, light amber; slight turbidity from lecithin — normal |
Visual after preparation |
| pH (prepared, 25°C) |
7.2 ± 0.2 |
pH meter (calibrated) |
| Neutralisation — QAC |
Growth promotion in presence of 0.1% benzalkonium chloride |
Challenge test per lot |
| Neutralisation — Paraben |
Growth promotion in presence of 0.1% methylparaben |
Challenge test per lot |
| Growth Promotion |
Good recovery of all 5 QC organisms per ISO 11133 criteria |
Inoculation test |
| Batch COA |
Available for every production lot |
On request or included |
Manufacturing & Documentation
Manufactured by AuSaMicS Pty Ltd
31 Longview CT, Thomastown VIC 3074, Australia | ABN 56 676 640 467
✓ Neutralisation efficacy tested per batch
✓ Full GHS-compliant documentation (COA, TDS, SDS)
✓ Australian stock — no import delays
✓ ISO 21149 / ISO 18415 / USP <61> compliant formulation
⚠️ Intended Use: For laboratory, pharmaceutical QC, and cosmetics microbiology use only. Not for human consumption or direct therapeutic use.