Fetal bovine serum - FBS

Serum supplements cell culture media

Serum products are often used in in vitro cell cultivation to supplement cell growth media. Media comes in liquid or powder form and must be hydrated and sterilized before use. For applications where animal-derived components are not a concern, basal media are often supplemented with serum, which acts as a source for growth factors, albumins, and other components that promote robust cell growth. Options for sera include FBS, bovine calf serum, engineered serum, and serum alternatives.

Benefits of fetal bovine serum

Fetal bovine serum provides nutrients, attachment factors, and other components for cells – including fibroblasts – in culture systems. Serum also acts as a buffer against pH fluctuations. It has high levels of growth promotion factors like macromolecular and carrier proteins that maximize cell growth. Since FBS is derived from fetuses, it’s naturally low in antibodies. For these reasons it’s the most common category of serum used.

FBS FAQs

Here are answers to some frequent questions regarding FBS.

What is the composition of FBS?

Fetal bovine serum contains many nutritional and macromolecular factors such as amino acids, lipids, and sugars. It has very low levels of antibodies and high levels of growth factors. Since FBS is derived from natural sources, the composition may differ between batches.

What are the types of FBS products?

There are many types of fetal bovine serum products that vary by source, processing, and testing. At Cytiva, we offer a broad range of sterile-filtered and quality-tested FBS products to meet different specifications. Each lot of serum is pooled after filtration and before dispensing. This step, called true pool processing, ensures uniformity and consistency between bottles. And it increases the consistency and quality of our serum products. Our FBS is derived from blood obtained in various countries, with most products sourced from the United States. There are three main categories:

• Defined FBS: premium serum for users with concerns about endotoxin levels. HyClone™ Defined FBS contains ≤ 5 EU/mL endotoxin and ≤ 15 mg/dL hemoglobin and is triple-filtered through serial 40-nm pore size-rated filters. The final serum is virus-tested according to 9 CFR 113.53 to demonstrate that there are no detectable levels of specified viruses, pathogenic agents, and hemadsorbing agents. Robust sterility testing further confirms that the final product contains no detectable growth of bacteria or fungi (current USP) and no detectable mycoplasma. Gamma-irradiated and heat-inactivated options are also available.
• Characterized FBS: HyClone™ characterized fetal bovine serum (FBS) offers traceability is provided back to the original source, as certified by the International Serum Industry Association (ISIA). Additional traceability testing of premium HyClone™ fetal bovine serum is performed by our collaborator, Oritain. This FBS product is filtered through three sequential 100 nm (0.1 µm) pore size-rated filters. Each lot of FBS is subjected to virus panel testing according to 9 CFR 113.53. HyClone™ characterized FBS is assayed for many components, including gamma globulin, glucose, and IgG. Additional treatments are available: HyClone™ FBS heat inactivated (HI) and HyClone™ FBS irradiated (IR). Additional testing, including EMEA-conforming testing, is also available.
• Standard FBS: commonly used in research applications for growth of common cell types. Heat inactivation, irradiation, and additional testing, including EMEA-conforming testing, is also available.

Other types of fetal bovine serum products include:

• Specialty products such as dialyzed FBS and USDA import-tested FBS
• Screened products like embryonic stem cell-screened and insect cell-screened FBS for specific applications

Common uses of FBS in cell culture

Fetal bovine serum is used for in vitro eukaryotic cell culture in:

• Vaccine production
• Biotechnology research and production
• Stem cell research
• Animal diagnostics
• Biopharmaceuticals