Quick Definition
What is FBS Ultra Low IgG?: FBS Ultra Low IgG is fetal bovine serum processed to reduce bovine IgG to less than 5 µg/mL — the industry standard for diagnostic-grade monoclonal antibody production and high-sensitivity immunoassay development where trace bovine IgG contamination would cause assay interference or reduce antibody purity below acceptable limits.
When is Ultra Low IgG required vs Low IgG FBS?
FBS Low IgG (<200 µg/mL) is sufficient for most research applications where final mAb purity after Protein A is >85%. FBS Ultra Low IgG (<5 µg/mL) is required when the mAb will be used as a diagnostic antibody where bovine IgG cross-reactivity creates false positives; when EU IVDR or FDA 510(k) submissions require demonstrated absence of bovine IgG interference; when the hybridoma produces <10 µg/mL mAb; or for therapeutic antibody research where xenogenic protein contamination must be minimised.
Key Facts
- FBS Ultra Low IgG: <5 µg/mL bovine IgG — confirmed by ELISA or RID per lot
- Standard FBS: 50–200 µg/mL bovine IgG — 10,000–40,000× more than Ultra Low IgG
- Equivalent to Gibco Ultra Low IgG FBS, Serana Ultra Low IgG, Sigma Low IgG — industry standard specification at <5 µg/mL
- Used at 10–15% in hybridoma production medium — same concentration as standard FBS
- Single Protein A step after Ultra Low IgG culture typically yields >95% pure murine IgG
- Not required for fusion and cloning phases — use standard FBS until production scale
Further Reading
SeamlessBio GmbH · Passau, Germany · info@seamlessbio.de
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