Why use Fetal Bovine Serum (FBS)?


For decades, Fetal Bovine Serum has been the first choice for supplementing cell culture media for the purpose of culturing cells. FBS is a complex mixture of defined and unknown growth factors, hormones, proteins, lipids, and minerals that are necessary for successful in vitro cell culture.


All of our Fetal bovine blood is collected from USDA approved abattoirs in the following countries: The United States, Australia, New Zealand, Canada, Mexico, and various states in Central America. The whole fetal blood is collected via cardiac puncture into 1L – 2L bags using a closed system. The blood is then allowed to clot at a refrigerated temperature. After being allowed to clot, the red blood cells are removed by refrigerated centrifugation. Finally, the raw serum is pooled into batches of 500L – 2,000L ( or 1,000-4,000 500 mL bottles) and frozen. Each lot is then pre-tested for endotoxin and hemoglobin levels to ensure that our stringent quality specifications are met.

Each lot of our FBS comes with a Certificate of Analysis (COA) and a Certificate of Origin (COO). The Certificate of Origin ensures that each lot is traceable back to the USDA abattoir in the country of origin.


Lots are triple 0.1 micron filtered, a process that has been validated to remove mycoplasma and adventitious agents. Serum is aseptically dispensed into gamma irradiated sterile bottles in a HEPA filtered Class 100 cleanroom.


FBS should be stored between – 5°C and – 80°C. Product stability is guaranteed for 5 years from the date of manufacture if stored properly. Omega does NOT recommend storage in an auto-defrost or frost-free freezer in which the FBS undergoes multiple freeze/thaw cycles.


Remove the bottle(s) from the freezer and allow it (them) to acclimate to room temperature for 10 minutes. Place each bottle into a water bath at 37°C and allow the material to completely thaw. Swirl the bottle(s) every 5 – 10 minutes to ensure complete thawing. After thawing, the FBS can be stored in a refrigerator for up to 3 weeks. Omega recommends that the FBS does not undergo multiple freeze/thaw cycles, additional aliquots should be made.

Turbidity or flocculent material may be observed upon thawing or prolonged storage in a refrigerator. This can be minimized by periodic swirling while the product is thawing. The precipitate or flocculent material is normal, non-toxic, and not detrimental to the performance of the FBS.


FBS is a biological product and there is inherent variability between each lot. Omega performs cell culture assays on each lot to ensure they meet a minimum growth rate, however no lot of FBS will work for every type of cell. Omega provides free samples upon request so that each end user can test the lot on their cells of interest before making a purchase.



  • FBS is tested for the absence of aerobic and anaerobic bacteria, molds, and fungi.

Endotoxin Testing

  • Endotoxin levels in FBS are determined by Gel-Clot LAL method.

Hemoglobin Testing

  • Hemoglobin concentration in FBS is determined by a colorimetric assay that measures the peroxidase activity of hemoglobin.

Mycoplasma Testing

  • FBS is tested for mycoplasma by the large batch Barile method for 28 days. Positive controls are inoculated and grown in parallel.

Viral Testing

  • FBS is tested for the absence of viruses.
  • Virus testing includes, but is not limited to:
    • Bovine Viral Diarrhea (BVD)
    • Infectious Bovine Rhinotracheitis (IBR)
    • Parainfluena Type 3 (PI3)
  • Additionally, all FBS imported from Canada, Mexico, and Central America must undergo USDA safety testing prior to release. USDA test screens for Bluetongue Virus and Akabane Disease.
  • Bovine Spongiform Encephelopathy (BSE)
  • The USDA considers the USA to be a BSE-Free country. The USDA also recognizes Australia, New Zealand, Mexico, Canada, and parts of Central America to be free of BSE. Raw blood is deemed to be free of BSE and FMD and eligible for importation into the USA for final processing and distribution.


Heat Inactivation (Cat # FB-02, FB-12)

  • FBS is thawed and then heated in a water bath at 56°C for 30 minutes. The bottle is continuously swirled to ensure complete inactivation of complement proteins.

Gamma Irradiation (Cat # FB-09, FB-19)

  • Serum is exposed to 2.5 – 3.5 mRads (25-35 kGy) of radiation. A Certificate of Irradiation accompanies each lot that undergoes gamma irradiation.

Dialysis (Cat # FB-03, FB-07)

  • Dialysis reduces the concentrations of low molecular weight components using a molecular weight cut-off of 10,000. FBS is dialyzed against 0.15M NaCl.

Charcoal Dextran Stripped / Treated (Cat # FB-04, FB-14)

  • Steroid and hormone concentrations in FBS are reduced using charcoal, dextran, and NaCl until progesterone concentration is less than 0.2 ng/ml. A hormone panel is performed pre and post-treatment.