FBS Low Endotoxin & Very Low Endotoxin — ≤5 EU/mL and ≤1 EU/mL
Endotoxin (lipopolysaccharide, LPS) is a component of the outer membrane of Gram-negative bacteria. Even at very low concentrations, endotoxin activates Toll-like receptor 4 (TLR4) signalling in sensitive cell types — triggering innate immune responses, pro-inflammatory cytokine release, and growth inhibition that can fundamentally alter experimental outcomes. Standard FBS lots may contain up to 10–25 EU/mL endotoxin. For many cell culture applications, this background is acceptable. For sensitive primary cells, stem cells, and immunological assays, it is not.
Which grade to choose: Low Endotoxin (≤5 EU/mL) is sufficient for most primary cell culture and general sensitive applications. Very Low Endotoxin (≤1 EU/mL) is required for macrophages, dendritic cells, TLR signalling studies, and any assay where endotoxin-driven cytokine background would confound results.
Cell Types Requiring Low Endotoxin FBS
| Cell Type | Why Endotoxin is Critical | Recommended Grade |
|---|---|---|
| Macrophages (RAW264.7, THP-1, primary BMDMs) | Express high TLR4 levels — endotoxin at ng/mL activates NF-κB, triggers TNF-α, IL-6, IL-1β release. Completely invalidates cytokine assays. | Very Low ≤1 EU/mL |
| Dendritic cells (primary monocyte-derived) | Endotoxin drives maturation — CD83, CD86 upregulation. Cannot study DC activation in standard FBS. | Very Low ≤1 EU/mL |
| Primary PBMC cultures | LPS-induced T cell and monocyte activation creates background that masks compound effects in immunological assays | Very Low ≤1 EU/mL |
| Embryonic stem cells / iPSC | Endotoxin activates innate immune pathways that affect pluripotency maintenance and differentiation | Very Low ≤1 EU/mL or ES Pre-Tested |
| Primary neurons, astrocytes | Neuroinflammatory activation via TLR4 — affects morphology, survival, and electrophysiology | Very Low ≤1 EU/mL |
| General primary cell culture | Reduces non-specific background in proliferation and viability assays | Low ≤5 EU/mL |
| Standard immortalised cell lines (HeLa, HEK293, CHO) | Usually not critical — standard FBS acceptable for routine culture | Standard FBS |
Specifications
| Parameter | Low Endotoxin | Very Low Endotoxin |
|---|---|---|
| Endotoxin limit | ≤5 EU/mL (LAL method) | ≤1 EU/mL (LAL method) |
| Sterile filtration | 0.1 µm — all lots | 0.1 µm — all lots |
| Mycoplasma | Tested — negative | Tested — negative |
| BVDV | Tested — negative | Tested — negative |
| Haemoglobin | ≤20 mg/dL | ≤20 mg/dL |
| Origin | EU and/or US | EU and/or US |
| Volumes | 100 mL, 500 mL, 1 L | Bulk on request | 100 mL, 500 mL | Bulk on request |
| Storage | −20°C | Batch reservation up to 6 weeks | −20°C | Batch reservation up to 6 weeks |
| Documentation | CoA, CoO, MSDS | CoA, CoO, MSDS |
FBS Portfolio — All Grades
| Product | Key Spec | Primary Use | Order |
|---|---|---|---|
| FBS Low & Very Low Endotoxin | ≤5 / ≤1 EU/mL | Primary cells, stem cells, sensitive lines | Order → |
| FBS Ultra Low IgG | <50 µg/mL IgG | Hybridoma, antibody production assays | Order → |
| FBS Tet-Free | <1 ng/mL tetracycline | Tet-On / Tet-Off inducible expression | Request → |
| FBS Heat Inactivated | 56°C / 30 min | Complement-sensitive assays, immune cells | Request → |
| FBS Gamma Irradiated | 25–45 kGy | GMP manufacturing, maximum viral safety | Request → |
| FBS ES Cell Pre-Tested | Pluripotency validated | Embryonic stem cells, iPSC, pluripotent lines | Request → |
Contact: info@seamlessbio.de | +49 851 37932226