What is FBS

What is FBS used for?

FBS is added to basal cell culture media (DMEM, RPMI 1640, MEM, F-12) to create a complete growth medium. It provides the complex mixture of growth factors, carrier proteins, and nutrients that most mammalian cells require to survive and proliferate in vitro. Without serum supplementation, most cell lines cannot maintain viability for more than 24–48 hours.

Key applications include: cancer cell line maintenance, primary cell culture, hybridoma production, viral vector manufacturing (AAV, lentivirus, adenovirus), vaccine production, stem cell research, and toxicology assays.

Why are there different FBS grades?

Standard FBS contains 50–200 µg/mL bovine IgG, 1–10 EU/mL endotoxin, and trace amounts of tetracycline — all of which interfere with specific assay types. Specialised grades remove or reduce these components for applications where they would confound results:

• FBS Low Endotoxin (<1 EU/mL): for cytokine assays, drug screening, AAV production
• FBS Low IgG (<200 µg/mL): for hybridoma mAb production with Protein A purification
• FBS Ultra Low IgG (<5 µg/mL): for diagnostic-grade antibody production
• FBS Heat Inactivated: for complement-sensitive assays and embryo culture
• FBS Tet-Free: for inducible expression systems (Tet-On/Tet-Off)

FBS alternatives

For applications requiring xeno-free or animal component-free conditions, FBS can be replaced with human platelet lysate (hPL), human AB serum, recombinant human albumin (rHSA) + defined growth factors, or chemically defined serum-free media. The correct alternative depends on the cell type and regulatory requirements.

Key Facts

• FBS is collected from bovine fetuses during slaughter of pregnant cows — the fetus is collected and blood is drawn via cardiac puncture under sterile conditions
• Standard FBS contains growth factors (IGF-1, EGF, FGF-2), albumin, transferrin, fibronectin, hormones, lipids and trace elements
• FBS is used at 5–20% concentration in cell culture medium — 10% is the most common standard concentration
• South American origin (Brazil, Argentina, Uruguay) is the global standard — OIE-certified negligible BSE risk
• Available in multiple grades: Standard, Low Endotoxin (<1 EU/mL), Low IgG (<200 µg/mL), Ultra Low IgG (<5 µg/mL), Heat Inactivated, Gamma Irradiated, Tet-Free, ES Cell Pre-Tested
• Lot-to-lot variability is the primary limitation — batch reservation is recommended for studies lasting more than 3 months
• All SeamlessBio FBS is processed and QC-tested in Germany with full CoA including sterility, mycoplasma, endotoxin, viral panel and cell culture performance test

Further Reading

• FBS Grades Explained — Which to Choose
• FBS Lot Testing Protocol
• FBS im Vergleich zu Humanserum
• What is Heat Inactivated FBS?
• Serum-Free Adaptation Guide

SeamlessBio GmbH · Passau, Germany · info@seamlessbio.de · +49 851 37932226