Serum Resources and FAQs

We have developed educational resources to answer top questions about the serum industry. From outlining the basics of FBS to understanding the rules, regulations, and how to mitigate risk – learn more by clicking through the sections below.

FBS Basics

    • Bovine serum is a by-product of the meat industry. Bovine blood may be taken at the time of slaughter, from adult cattle, calves, very young calves or (when cows that are slaughtered are subsequently found to be pregnant) from bovine fetuses.

    • Blood is available from bovine fetuses only because a proportion of female animals that are slaughtered for meat for human consumption are found to be pregnant.

    • Serum is the amber-colored blood fraction remaining after the natural coagulation of blood; it is typically further refined via centrifugation, which serves to remove remaining blood cells.  There are no deletions or additions (including preservatives) allowed.

    • Fetal bovine serum (FBS) is the serum derived from blood drawn from a bovine fetus via a closed system of collection in a facility that is approved by the national competent authority.

    • Whilst the procedure of making serum may seem to be straightforward, the processing of serum takes place under very tightly controlled conditions. The process has been carefully developed and uses sophisticated facilities and equipment, accompanied by extensive testing. The levels of control and testing are particularly stringent when processed bovine serum is intended for use in the production of medicinal products.

    • Fetal bovine serum (FBS) is used as a growth supplement for the in vitro cell culture of eukaryotic/mammalian cells. Animal sera—both bovine and non-bovine sera—are used in cell culture applications with the most widely used being fetal bovine serum.

    • FBS contains 1000+ components, including proteins, electrolytes, lipids, carbohydrates, hormones, enzymes, and other undefined constituents, It also contains very low levels of antibodies, allowing for versatility in many different cell culture applications.

    • FBS is typically used at a concentration of 5–10% in a basal medium

    • FBS composition is undefined, and therefore can vary from lot-to-lot

Serum and Origin
What are you buying

  • Serum: Serum is the liquid fraction of clotted blood. It is depleted of cells, fibrin and clotting factors. Serum differs from plasma in that anti-coagulant is never added to the blood after collection from the animal. Serum is prepared by centrifuging until the clot and remaining blood cells are separated from the liquid phase. The serum is then removed and stored frozen pending further processing.

    Fetal Bovine Serum: Semi-processed or raw Fetal bovine serum (FBS) is obtained as described above from the blood of fetuses of healthy, pre-partum bovine dams that have been subjected to ante and/or post-mortem veterinary inspection. It is collected in abattoirs inspected by the competent authority in the country of origin. Fetal blood is collected aseptically using cardiac puncture, thereby reducing the risk of microbial contamination and resultant endotoxins. Collection occurs in an area of the abattoir specifically set aside for this purpose to minimize the risk of contamination by other fluids.  There are no deletions or additions (including preservatives) allowed.

    Specialty Fetal Bovine Serum: This is semi-processed FBS or sterile filtered FBS that has been subjected to one or more modification processes. Examples are Dialyzed, Charcoal Stripped, Ultra-low IgG, ES Cell, MSC and Exosome-Depleted.

    Newborn Calf Serum: Newborn Calf Serum (NBCS) is defined as the liquid fraction of clotted blood derived from healthy, slaughtered bovine calves aged less than 20 days, deemed fit for human consumption through ante- and/or post- mortem inspection. It is collected in abattoirs inspected by the competent authority of the country of origin. There are no deletions or additions (including preservatives) allowed.

    Donor Bovine Serum (also known Donor Calf Serum): Donor-sourced Bovine Serum (DBS) is defined as the liquid fraction of clotted blood derived from healthy cattle 12 months of age or older from controlled donor herds whose health status is confirmed by regular inspection by competent, legally authorized veterinarians.

    Bovine Serum (also known as Adult Bovine or Calf Serum): Bovine Serum is defined as the liquid fraction of clotted blood derived from healthy, slaughtered cattle 12 months of age or older, deemed to be fit for human consumption by ante- and/or post- mortem inspection. It is collected in abattoirs inspected by the competent authority of the country of origin.

  • The ISIA has developed definitions of origin, based on international guidelines set by the WTO, OIE, as well as the USDA and the EU.  Since the word “origin” has several meanings and can cause confusion and controversy, the ISIA suggests the use of very precise wording whenever possible. 

    Country of Collection: This is the country where the animal was slaughtered and the blood was collected or, in the case of donor animals, where the blood was collected. This includes animals born and raised in the country of collection, as well as imported animals, and may include animals imported for immediate slaughter. This is the country shown on the label as “origin”. The Country of Collection is required to be shown on the Certificate of Analysis (CoA) and Certificate of Origin (CoO). The process of collecting blood and separating serum is considered substantial transformation.

    Country of Manufacturing: This is the country where filtration, bottling, and labeling occur and includes any other processes performed prior to filtration and bottling. Other acceptable terms include “Manufacturing Address” or “Site of Manufacture”. This should be listed on the CoA. This is not considered substantial transformation.

    Country of Further Treatment: This is the country in which the product is treated after sterile filtration. Examples of further treatment are gamma irradiation or heat inactivation.  These processes should be listed individually on the CoA and are not considered substantial transformation.

    The Country of Collection (“origin” on the label) does NOT change for import/export purposes. The Country of Collection can never change.

Production and Testing

  • 9CFR virus testing: Virus panel testing according to Code of Federal Regulations, (CFR), Title 9, Part 113.53 (c) [113.46, 113.47]. Detected by fluorescent antibody.

    Biochemical and hormone profile: Quantification of biochemical and hormonal (estradiol, insulin, progesterone, testosterone, and thyroxine) profiling that may have impact on cell culture.

    BSE status: BSE (bovine spongiform encephalopathy) is a disease for which the WOAH (The World Organization for Animal Health) has established official recognition of the sanitary status of countries and zones. Regions that have negligible risk of bovine spongiform encephalopathy (mad cow disease) have lesser biosafety risk for import.

    EMA virus testing: Virus panel testing according to Code of Federal Regulations, (CFR), Title 9, Part 113.53 (c) [113.46, 113.47]. Detected by fluorescent antibody.

    Endotoxin testing: Endotoxin is directly related to the quality of collection and processing of serum, the higher the level, the more introduction to gram-negative bacteria.

    Filtration: Triple (0.1 µm) filtration: Aseptic process that has been validated to ensure that all products meet the industry standard sterility assurance level of 10-3.

    Haemoglobin/hemoglobin: Indicator of proper and/or improper collection and processing of blood and/or serum.

    Mycoplasma and Mycoplasma supplemental testing (H-Stain): Direct culture and Hoechst stain. Testing indicates Mycoplasma - Not Detected.

    Origin confirmation: We use a proprietary fingerprinting technology to confirm FBS origin and eliminate the potential for counterfeit product.

    Osmolality: Osmolality of FBS, a measure of the concentration of solutes like salts and sugars, should be similar to culture media to avoid osmotic shock that may impact cell viability.

    Performance: relative growth promotion (RGP): The growth promotion assay measures the ability of each FBS lot to support proliferation of fastidious human diploid fibroblasts through multiple subcultures.

    pH: relative pH promotion: Serum acts as a buffer in the cell culture system; the pH is tested to ensure accurate cell culture quality and performance.

    Total protein: FBS is rich in a variety of proteins that can impact cultured cells; the total protein in serum is measured by taking a chemistry panel of the serum.

  • How is FBS Produced and Tested?

    • Fetal bovine blood is collected using equipment designed to prevent microbial contamination, and carefully monitored procedures.

    • The process takes place in a separate specially constructed area in the slaughterhouse/abattoir under clean, controlled conditions.

    • The aseptically collected fetal blood is refrigerated immediately and allowed to clot. It is then centrifuged to separate the serum from the blood clot. The serum is kept frozen in carefully identified clean, hygienic containers until it is thawed immediately prior to further processing.

    • A pre-defined quantity of serum is processed and tested to form what is called a “batch” or “lot” of finished product. Processing of each batch is performed under controlled conditions by 

      • Thawing the designated material in a controlled environment and pooling it

      • “Sterile Filtration” passing the material through a series of membrane filters with tiny pores of reducing size, the last of which will have a pore size that is small enough to remove and retain bacteria and fungi

      • The batch is frozen again immediately after filtration to preserve its quality.

    • Samples are carefully tested using approved tests to confirm freedom from bacteria and other microorganisms. Extensive biochemical and biological testing are also performed.

    • Viruses are not removed by sterile filtration. Therefore, the batch must be tested to ensure that it is free from contaminating viruses. The method of choice for viral removal is gamma irradiation.  To view articles on gamma irradition, click here

    • Records are kept ensuring that each process step and the results of all testing can be linked directly to each individual batch of serum

    • The customer may also perform tests on the batch prior to purchase. This usually includes checks to confirm that the batch will perform optimally with the customer’s specific cell lines of interest.

    • The overall testing process is very labor intensive and may take several months to complete.

Availability and Uses

  • Fetal bovine serum (FBS) is a byproduct of the meat industry. No one can influence the amount of FBS available. Drought, high feed prices and high beef demand leads to more available FBS. Milk prices can also impact the availability of FBS as dairy cows are culled when there is an oversupply of milk. Then when farmers are rebuilding their herds, there is less FBS on the market. The result? The price and availability of FBS can be difficult to predict.

  • Both academic and industrial researchers and scientists in manufacturing environments use fetal bovine serum (FBS) in their cell culture media for a range of applications. The ability to maintain animal cells outside the body was demonstrated more than one hundred years ago. Currently, this technology is used in basic research as well as

    • Vaccine production

      • In the 1940s and 1950s techniques were refined to produce cell cultures that could be used to cultivate viruses (which will only grow in living cells). This led to the first virus vaccine to be produced using cell culture – polio vaccine, in 1955. The contribution to human and animal health of the vaccines that have resulted from the application of this technology is an ongoing global success story.

    • Biopharmaceuticals

      • More recently cell culture has been combined with what are called recombinant techniques to develop recombinant-derived products (“biopharmaceuticals which offer important new opportunities for treatment and diagnosis"). This is a hugely important and very rapidly expanding area of modern medicine.

    • Safety testing

      • Another significant application of cell culture is in the safety testing of widely used products such as cosmetics and household chemicals. As the use of live animals for testing of such products has become increasingly controversial cell culture has been used more and more to reduce or eliminate testing in animals.

Rules and Regulations

    • The rules and regulations that processors of bovine serum must respect are complex and change often.

    • Some regulations directly affecting finished bovine serum, apply to other materials of animal origin as well. They are in place to ensure that the movement of products from one country to another, and their subsequent manipulation, does not pose a risk to animal or human health.

    • When bovine serum, or other materials of animal origin, are used in the manufacture of products such as pharmaceuticals, additional rules are in place to ensure that the material can safely be used in its intended application.

    • Export and import of animal by-products such as bovine serum necessarily involves collaboration between different national and international regulatory bodies.

    • Information on the animal health status of countries/regions provided by the WOAH is the basis upon which decisions relating to the movement of animal by-products are made.

    • Veterinary controls worldwide are often based upon the rules and regulations established by the United States Department of Agriculture (the USDA) and by the European Commission – the two largest global markets for animal-derived products being the USA and Europe.

    • Bovine serum has a long and extensive history of safe use in the manufacture of human and veterinary pharmaceutical products and in other applications as well.

    • Serum (together with other animal-derived materials) destined for use as a raw material in the manufacture of medicinal products is subject to particularly stringent additional requirements relating to quality and safety.

    • Numerous regulatory bodies worldwide are involved in setting standards and defining requirements that impact bovine serum either directly or indirectly.

      • In the USA these are the USDA, the Food and Drug Administration (FDA) and the United States Pharmacopoeia.

      • Both USDA and FDA have in place regulations that address in detail the control of bovine serum that is to be used in the manufacture of medicinal products.

      • In Europe the bodies are the European Commission, the European Directorate for the Quality of Medicines and Healthcare (EDQM which is responsible, for the European Pharmacopoeia) and the European Medicines Agency (EMA).

    • Scientific advice is also issued by supra-national organizations such as the World Health Organization (WHO) and the World Organization for Animal Health (WOAH).

How to mitigage risk

  • This overview of the key precautions taken to significantly reduce possible risks is driven by the use of FBS in pharmaceutical/vaccine manufacture

    • The conditions and methods of slaughter, collection, storage, manipulation, processing, treatment, testing, and transport are all very carefully controlled to minimize the risk of the serum contamination with living microorganisms or undesirable non-living material.

    • Bovine blood is only collected in countries that have a known, well-monitored, documented and acceptable animal health status. ISIA member companies and regulatory authorities make use of the information published by the World Organization for Animal Health (the “WOAH”) in deciding which countries are acceptable. The WOAH (an intergovernmental organization) is responsible for establishing and publishing the animal health status of countries/regions.

    • The diseases monitored by WOAH include many diseases that are transmitted from animal to animal (e.g., foot and mouth disease) and also potentially zoonotic diseases (i.e., transmissible from animals to human).

    • Source countries must also have in place an infrastructure that includes authority-licensed slaughterhouses/abattoirs, acceptable to national and international bodies and dedicated to the processing of healthy animals. The animals must be inspected by qualified authority-recognized experts before slaughter, and meat from the animals must be passed as fit for human consumption.

    • ISIA member companies have Quality Assurance systems for the monitoring and evaluation of equipment, facilities, and training of staff.

    • As an additional safeguard fetal bovine and donor serum is often gamma irradiated using controlled procedures in facilities specially validated for this purpose. To learn more about Gamma irradiation, click here.

    • All the above is comprehensively documented to ensure that procedures can be seen to have been followed, and that relevant test results are available for every step and for every batch of processed serum that is produced.

    • The “traceability” of all the material that makes up each batch of serum from collection to product is recognized by ISIA member companies as being imperative; it provides the necessary assurances that a specified batch of serum cannot have been substituted with another of unknown quality (and thus unknown safety). The ISIA has therefore established a very comprehensive traceability policy. Click here.

BSE

  • "May 19, 2023, Atypical BSE detection does not change the negligible risk status of the United States." Click here for more information

    • Bovine Spongiform Encephalopathy (BSE, “Mad Cow Disease”) has been very much in the spotlight in the past. Because humans are susceptible to BSE, one of the questions asked is: “What precautions are in place to prevent the transmission of this disease via medicinal products that have been manufactured using bovine serum?”

    • Guidance on this applies to a wide range of ruminant-derived materials and focusses on risk minimization. In order to establish compliance, companies must submit detailed information covering all aspects of sourcing, collection and processing for expert review.

    • There is no evidence that BSE has ever been transmitted via a medicinal product and experts have documented that no infectivity has been found in the blood of afflicted cattle.

    • Although BSE is a relatively new disease, similar diseases called transmissible spongiform encephalopathies (TSEs) have been known for a long time in both animals and humans.

      • The exact nature of the agents that cause these TSEs is still under investigation, but they are very resistant to many of the chemical and physical treatments that efficiently destroy bacteria, viruses, and other microorganisms.

      • It is not possible to effectively “treat” a material like bovine serum to inactivate the BSE agent, so precautions must be taken to ensure that the material is free from the BSE agent at the outset and that it is manipulated in such a way as to avoid its introduction.

    • The WOAH monitors the incidence of BSE in the world and publishes this information on a regular basis. Regulatory authorities and processors use it as one of the critical determinants in deciding which countries may be used as a source of serum.  Click here to view WOAH website.

    • BSE is a disease of older animals. This gives rise to an additional safeguard. Source animals for bovine serum must be less than three years old – a cut-off that is based upon scientific input and consensus