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LB Agar (Lennox) (AS-1268) – Low-Salt Medium for Bacterial Culture
$32.50 AUD
LB Agar (Lennox)
Reduced-Salt Bacterial Culture Medium for Molecular Microbiology
Catalogue No: AS-1268
Reduced-Salt Bacterial Culture Medium for Molecular Microbiology
Catalogue No: AS-1268
E. coli Cloning & Plating
Reduced NaCl 5 g/L
Salt-Sensitive Strains
Lennox Formulation
Australian Made
QC Certified
Overview
LB Agar (Lennox) is a nutritionally rich, non-selective solid culture medium developed by Lennox in 1955 for the growth and maintenance of Escherichia coli in molecular microbiology applications. It is particularly suited to recombinant E. coli K-12 strains requiring enriched media for optimal growth and plasmid stability.
Compared to LB Agar (Miller), the Lennox formulation contains reduced sodium chloride at 5.0 g/L — providing lower osmolarity (~220 mOsm/kg vs ~310 mOsm/kg for Miller) — making it well suited to salt-sensitive strains, improved transformation efficiency, and stable plasmid propagation.
Composition (per litre)
| Component | CAS Number | Function | Amount |
|---|---|---|---|
| Tryptone | 73049-73-7 | Nitrogen, carbon, amino acids | 10.0 g |
| Yeast Extract | 8013-01-2 | Vitamins, growth factors | 5.0 g |
| Sodium Chloride | 7647-14-5 | Osmotic balance (Lennox — reduced) | 5.0 g |
| Agar | 9002-18-0 | Solidifying agent | 15.0 g |
| Final pH | 7.0 ± 0.2 at 25 °C | ||
LB Formulation Comparison
| Component | Lennox (AS-1268) | Miller (AS-1267) | Bertani |
|---|---|---|---|
| Tryptone | 10.0 g/L | 10.0 g/L | 10.0 g/L |
| Yeast Extract | 5.0 g/L | 5.0 g/L | 5.0 g/L |
| NaCl | 5.0 g/L | 10.0 g/L | 0 g/L |
| Agar | 15.0 g/L | 15.0 g/L | 15.0 g/L |
| Osmolarity | ~220 mOsm/kg | ~310 mOsm/kg | ~110 mOsm/kg |
| Best for | Salt-sensitive strains, transformation | Standard E. coli default | Very low osmolarity |
Applications
- Cloning & Routine Culture: DH5α, BL21, TOP10, JM109 and other standard E. coli strains
- Salt-Sensitive Strains: E. coli K-12 derivatives where reduced NaCl improves growth and plasmid stability
- Transformation: Lower ionic strength supports optimal transformation efficiency
- Antibiotic Selection: Ampicillin, kanamycin, chloramphenicol, tetracycline selection plates
- Phage Work: Reduced NaCl favours lambda phage propagation
- Teaching: Standard molecular microbiology instruction and general bacterial cultivation
Preparation
- Suspend 35.0 g in 1 litre of demineralised or purified water.
- Mix thoroughly and heat with agitation until fully dissolved.
- Adjust pH to 7.0 ± 0.2 if required (1 M NaOH or 1 M HCl).
- Sterilise by autoclaving at 121 °C for 15 minutes.
- Cool to 45–50 °C.
- Add filter-sterilised antibiotics or supplements aseptically.
- Dispense 20–25 mL per 90 mm sterile Petri dish.
- Allow to solidify on a level surface before use.
Common Antibiotic Concentrations
| Antibiotic | Working Concentration | Application |
|---|---|---|
| Ampicillin | 100 µg/mL | Amp-resistant plasmid selection |
| Kanamycin | 50 µg/mL | Kan-resistant plasmid selection |
| Chloramphenicol | 25 µg/mL | Cm-resistant selection |
| Tetracycline | 12.5 µg/mL | Tet-resistant selection |
| Gentamicin | 10 µg/mL | Gm-resistant selection |
Storage
| Dehydrated powder | 15–30 °C, tightly closed container |
| Plates (no antibiotics) | 2–8 °C, inverted, up to 4 weeks |
| Plates (with antibiotics) | 2–8 °C, use within 1–2 weeks |
| Do not use if | Contamination, colour change, or cracking of agar surface observed |
For laboratory research and educational use only. Not for diagnostic, clinical, food, or veterinary applications. AuSaMicS Pty Ltd | ABN 56 676 640 467 | www.ausamics.com.au
Product Identification
| Product Name | LB Agar (Lennox) |
| Catalogue Number | AS-1268 |
| HS Code | 3821.00.00 |
| Physical Form | Fine homogeneous powder |
| Colour (powder) | Light beige to cream |
| Colour (prepared) | Clear to slightly amber solid agar |
| Original Reference | Lennox E.S. (1955) Virology 1:190–206 |
| ATCC Medium | ATCC Medium 1065 |
Composition (per litre)
| Component | CAS Number | Function | Amount |
|---|---|---|---|
| Tryptone | 73049-73-7 | Nitrogen, carbon, amino acids | 10.0 g |
| Yeast Extract | 8013-01-2 | B-vitamins, growth factors | 5.0 g |
| Sodium Chloride | 7647-14-5 | Osmotic balance — Lennox reduced-salt | 5.0 g |
| Agar | 9002-18-0 | Solidifying agent | 15.0 g |
Total: 35.0 g/L | pH: 7.0 ± 0.2 at 25 °C | NaCl: 5.0 g/L | Osmolarity: ~220 mOsm/kg
Physical & Chemical Specifications
| pH (prepared, 25 °C) | 7.0 ± 0.2 |
| Moisture (loss on drying) | ≤ 5.0% |
| Gel strength | Firm agar — 20–25 mL per 90 mm Petri dish |
| NaCl concentration | 5.0 g/L — Lennox reduced-salt formulation |
| Osmolarity (approx.) | ~220 mOsm/kg (vs ~310 mOsm/kg for Miller) |
| Selectivity | Non-selective |
| Differential | Non-differential |
Performance Characteristics
| Organism | ATCC No. | Expected Result | Incubation |
|---|---|---|---|
| E. coli K-12 | 23716 | Good growth — cream 1–3 mm colonies | 37 °C, 12–18 h |
| E. coli DH5α | N/A | Good growth — cloning host | 37 °C, 12–16 h |
| E. coli BL21(DE3) | N/A | Good growth — expression host | 37 °C, 12–16 h |
| E. coli TOP10 | N/A | Good growth — cloning host | 37 °C, 12–16 h |
| Salmonella typhimurium | 14028 | Good growth | 37 °C, 18–24 h |
Quality Standards
| Original Reference | Lennox E.S. (1955) Virology 1:190–206 |
| Standard References | Sambrook & Russell — Molecular Cloning; Current Protocols in Molecular Biology |
| ATCC Medium | ATCC Medium 1065 |
| Country of Manufacture | Australia |
For laboratory and research use only. AuSaMicS Pty Ltd | ABN 56 676 640 467 | www.ausamics.com.au
GHS Classification: Not classified as hazardous (AU WHS Regulations 2011) | Signal Word: None | ADG: Not regulated
Section 1 — Identification
| Product Name | LB Agar (Lennox) |
| Catalogue Number | AS-1268 |
| Intended Use | Non-selective solid culture medium — laboratory research, molecular biology, and educational use only |
| Supplier | AuSaMicS Pty Ltd | 31 Longview CT, Thomastown VIC 3074 |
| ABN | 56 676 640 467 |
| Emergency Phone | +61 412 520 598 |
| support@ausamics.com.au |
Section 2 — Hazard Identification
Not classified as hazardous according to GHS criteria (AU WHS Regulations 2011). No hazard pictograms, signal word, or hazard statements required. Standard laboratory precautions apply.
Section 3 — Composition
| Component | CAS Number | Proportion | Classification |
|---|---|---|---|
| Tryptone | 73049-73-7 | ~28.6% | Not classified |
| Yeast Extract | 8013-01-2 | ~14.3% | Not classified |
| Sodium Chloride | 7647-14-5 | ~14.3% | Not classified |
| Agar | 9002-18-0 | ~42.8% | Not classified |
Section 4 — First Aid
| Inhalation | Remove to fresh air. Seek medical advice if symptoms persist. |
| Skin Contact | Wash thoroughly with soap and water. |
| Eye Contact | Flush with water for at least 15 minutes. Seek medical advice if irritation persists. |
| Ingestion | Rinse mouth. Seek medical advice if large quantities ingested. |
Section 7 — Handling & Storage
| Handling | Standard lab precautions. Avoid dust. Wash hands after use. |
| Storage (powder) | 15–30 °C, tightly closed, dry, away from moisture and light |
| Storage (plates) | 2–8 °C, inverted; with antibiotics use within 1–2 weeks |
Section 8 — Personal Protection
| Respiratory | Dust mask (P1) if handling in poorly ventilated area |
| Eye protection | Safety glasses recommended |
| Gloves | Disposable nitrile or latex laboratory gloves |
Section 13 — Disposal
Autoclave inoculated plates (121 °C, 30 min) before disposal. Dispose of unused powder as general laboratory waste in accordance with local regulations.
Section 14 — Transport
Not classified as dangerous goods under ADG, IATA, or IMDG. No special transport requirements.
⬇ Download Full SDS — 16 Sections (PDF)Prepared in accordance with Australian WHS Regulations and GHS 7th Edition. AuSaMicS Pty Ltd | ABN 56 676 640 467 | www.ausamics.com.au | Version 1.0 — March 2026
Product Information
| Product Name | LB Agar (Lennox) |
| Catalogue Number | AS-1268 |
| Lot / Batch Number | Contact us for batch-specific COA |
| Manufacturing Date | Available on request |
| Expiry Date | Available on request |
| Storage Conditions | 15–30 °C, tightly closed, dry |
Specification & Test Results
| Test | Specification | Typical Result | Status |
|---|---|---|---|
| Appearance (powder) | Light beige to cream fine powder | Complies | ✓ PASS |
| Appearance (prepared) | Clear to slightly amber solid agar | Complies | ✓ PASS |
| pH (prepared, 25 °C) | 7.0 ± 0.2 | 7.0 | ✓ PASS |
| Moisture (loss on drying) | ≤ 5.0% | Complies | ✓ PASS |
| Gel formation | Firm, clear agar gel | Complies | ✓ PASS |
| Sterility (prepared medium) | No microbial growth | Complies | ✓ PASS |
| E. coli K-12 ATCC 23716 | Good growth — cream 1–3 mm colonies | Complies | ✓ PASS |
| NaCl content (Lennox) | 5.0 ± 0.3 g/L | Complies | ✓ PASS |
| Agar gel strength | Firm gel — 20–25 mL per 90 mm plate | Complies | ✓ PASS |
Authorisation
| Released by | Hassan Salimi |
| Title | Founder and Technical Director |
| Organisation | AuSaMicS Pty Ltd |
Need a batch-specific COA?
Contact us with your order number and we will issue a full COA within 1 business day.
support@ausamics.com.au | +61 412 520 598
⬇ Download Certificate of Analysis (PDF)
Contact us with your order number and we will issue a full COA within 1 business day.
support@ausamics.com.au | +61 412 520 598
This Certificate of Analysis is issued by AuSaMicS Pty Ltd and is valid for the batch identified above. Results apply to the specific lot tested and are not transferable. AuSaMicS Pty Ltd | ABN 56 676 640 467 | www.ausamics.com.au