FAQ - Frequently Asked Questions

  1. What is Bovine Serum?
  2. Where does Bovine Serum come from?
  3. What is Fetal Bovine Serum?
  4. What is FBS used for?
  5. Why do cell cultures need serum?
  6. How is FBS collected?
  7. What makes Biowest a serum specialist?
  8. What makes Biowest unique?
  9. How should I select my FBS supplier?
  10. What is the OIE (World Organization for Animal Health)?
  11. What does USDA Approved mean?
  12. What does ISIA mean?
  13. What about bovine viruses?
  14. Foot and mouth disease (FMD): does it matter?
  15. Are some FBS origins better quality than others?
  16. Why is Australian FBS so expensive?
  17. Why do prices differ from different countries?
  18. Why is FBS less expensive in Europe than in the USA?
  19. What is FBS global supply?
  20. Why is the demand for FBS increasing?
  21. Do I need to test FBS from Biowest?
  22. Is it necessary to heat inactivate serum?
  23. How should the serum be heat inactivated?
  24. Why is FBS sometimes gamma irradiated?
  25. Does gamma irradiation affect FBS performances?
  26. What are the sampling rules for sterility tests on sera?
  27. How are the samples tested for viruses?
  28. Why not use PCR testing for viruses?
  29. What is BSE?
  30. What is the risk of BSE in serum products?
  31. What makes Fetal Bovine Serum (FBS) unique?
  32. Are there alternatives to FBS?
  33. What is the recommended storage temperature for the serum?
  34. How long can the serum be stored between +2 to +8°C?
  35. What are the deposits in the serum?
  36. What is the best way to thaw serum?
  37. Are Biowest products sterile?
  38. How do I select FBS for stem cells?
  39. Is it normal that the trypsin products do not always have the same color?
  40. Why is traceability important?
  41. How does Biowest guarantee traceability?
  42. What about animal welfare?
  43. Why kill pregnant animals?
  44. Do the animals suffer?
  45. What are the ethics?
  46. What about regulations and conformity?
  47. What about misrepresentation and smuggling?
  48. What is adulteration?

What is Bovine Serum?

Serum is the centrifuged fluid component extracted from either clotted or defibrinated whole blood. Bovine serum comes from blood taken from domestic cattle.
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, and is accompanied by extensive testing particularly stringent when processed bovine serum is intended for use in the production of medicinal products.

Where does Bovine Serum come from?

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. It is also obtained from what are called "donor" animals which give blood more than once.

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

Bovine serum is categorized according to the age of the animal from which the blood was collected as follows:

  • "Fetal bovine serum" comes from fetuses
  • "Newborn calf serum" comes from calves less than three weeks old
  • "Calf serum" comes from calves aged between three weeks and 12 months
  • "Adult bovine serum" comes from cattle older than 12 months

What is Fetal Bovine Serum?

Fetal Bovine Serum (FBS) comes from the blood drawn from a bovine fetus via a closed system of collection at the slaughterhouse. Fetal Bovine serum is the most widely used serum supplement for the in vitro cell growth factors because of its high content of embryonic growth promoting factors.

What is FBS used for?

There is a wide range of applications for fetal bovine serum. The most important is in the field of biopharmaceuticals and vaccines.  It is used in the research, manufacture and control of human and veterinary vaccines and of drugs, many of which are at the cutting edge of drug development.
Fetal bovine serum is also used extensively in research. A technique known as "Cell culture" is widely applied in the manufacture of both vaccines and bio-pharmaceuticals in which bovine serum is broadly used. 

Why do cell cultures need serum?

Maintaining cells in vitro in a healthy condition and over time is a complex task. They will only survive, grow and multiply if they are well fed and provided with an appropriate and protective environment. Complex mixtures of substances ("media") are used to bathe the cells in order to both feed and protect them. Different cells have different requirements. In many instances the presence of serum in the mixture is essential if the cells are to grow adequately and normally. Bovine serum is much the most widely used, because high quality bovine serum is available in sufficient volume and has been found to support cell growth very well indeed.

How is FBS collected?

FBS is collected from the fetuses of pregnant cows, slaughtered in compliance with the OIE (World Animal Health Organization) guidelines and internationally accepted standards of veterinary inspection.

What makes Biowest a serum specialist??

With more than 25 years of experience with serum as its main activity, Biowest is dedicated to quality and service; to vertical integration, and providing a wide range of origins.

What makes Biowest unique?

Biowest takes full responsibility of ensuring a vertically integrated supply chain to the highest standard of quality, traceability and safety. In 2004, Biowest was acquired by the Viking/Serascandia group to become the first vertically integrated serum company. In the same year, Biowest denounced cases of misrepresentation to the authorities and informed the affected victims; highlighting the importance of serum industry traceability guidelines and oversight, and promoting the creation of the International Serum Industry Organization.

How should I select my FBS supplier?

The choice of the FBS supplier is based on Quality, Traceability and Safety along the whole supply chain, endorsed by comprehensive documentation; backed up by audits of the supply chain back to the serum source; and covering several years.

What is the OIE (World Organization for Animal Health)?

The OIE (World Organization for Animal Health) is an intergovernmental organization created in 1924.
In 2011, the OIE totaled 178 Member Countries and Territories.

Its missions are:

  • To ensure transparency in the global animal disease situation
  • To collect, analyze and disseminate veterinary scientific information
  • To provide expertise and encourage international solidarity in the control of animal diseases
  • To safeguard world trade by publishing health standards for international trade in animals and animal products
  • To improve the legal framework and resources of National Veterinary Services Organization

What does USDA Approved mean?

The serum's source is from a USDA Approved country. This means that serum is produced from blood collected in countries that have been approved by the United States Department of Agriculture (USDA) to export ruminant serum products to the United States. Eligible countries that export fetal bovine serum into the U.S. include: Australia, Canada, Chile, Costa Rica, El Salvador, Guatemala, Honduras, Mexico, New Zealand, Nicaragua, and Panama.

What does ISIA mean?

ISIA is the International Serum Industry Association. Its main objective is to establish traceability guidelines and harmonize international import rules, working with government and international authorities.

What about bovine viruses?

Some cattle viruses can cross the placenta of the cow and infect the calf fetus, thus contaminating FBS and potentially making it unsuitable for use in cell culture. Some of these cattle viruses have a limited distribution and only exist in certain parts of the world.  These are viruses of concern when importing FBS from infected countries - See Table of Diseases of Importation Concern for FBS. Other cattle viruses exist in all countries, and regardless of country of origin, the FBS must be tested or treated to assure freedom from these and other viruses (See USDA 9 CFR 113.53 and EMEA-CPMP-BWP-1793-02). The treatment of choice for most FBS is gamma irradiation at 25-45 kGy to guarantee freedom from viruses.

Foot and mouth disease (FMD): does it matter?

FMD is relevant for regulatory import purposes but not for cell growth. The USA and a few other countries only allow FBS imports from countries free from FMD, WITHOUT vaccination while most other countries also accept FMD-free WITH vaccination. Both types of FMD-free countries are free of FMD outbreaks and circulating FMD viruses, as verified by the OIE and declared equally safe.

Are some FBS origins better quality than others?

The serum's origin has no influence on cell growth. Biowest has compared cell growth in FBS from seven different countries on three continents, and confirmed that regardless of the country of origin, all cell lines tested had the same average performance. One batch of FBS may work well for one specific cell line, but not for another. "Serum quality" is specific for each cell line. That is why testing of FBS is widely used when dealing with sensitive cell lines. Biowest performs the most extensive analysis of biochemical parameters and testing on cell lines in the industry, making available the results on the Certificates of Analysis.

Why is Australian FBS so expensive?

Australian FBS prices are higher because Australia is perceived to be a "safer" origin for BSE and cattle viruses. Canada and Australia were the first countries outside the USA where FBS was produced. In the 1980s, BSE cases that occurred in North America became a strong argument in favor of Australian FBS. The point was made that being "isolated", Australia was necessarily the most secure origin.

However, BSE has never been found in young animals, let alone in fetuses, and BSE transmitted by animal feed has been eradicated. The remaining BSE cases are the spontaneous BSE events, which occur in all cattle populations (Stanley B. Prusiner, Nobel Prize 1997). All countries find spontaneous BSE cases if their sanitary surveillance systems are sensitive enough. Additionally, the OIE veterinary authorities have declared all blood and blood product, regardless of country of origin, to be safe in terms of BSE. So, the BSE arguments in favor of Australia were clearly ill founded from the beginning, and have become obsolete.

Nevertheless, Australian FBS is still sold as "safer", at much higher prices than other origins. Paradoxically, Australia is actually among the countries with the most types of viruses of import concern, including Blue Tongue, Akabane, Aino, and Bovine Ephemeral Fever  (see FAQ #13). Like in the tale "The Emperor's new clothes", by Danish writer Hans Christian Andersen, those who believe that paying more will assure them a better serum, are being misled.

Why do prices differ from different countries?

A huge price difference exists between countries classified as "FMD-Free-without-vaccination" for which demand exceeds supply, and countries listed as "FMD-Free-with-vaccination" where supply historically has exceeded demand. The price difference has been several hundred per cent, whereby serum users in the US have paid billions of USD more than serum users in the EU. Proposals from USDA to harmonize US and EU import rules for FBS relating to FMD (following OIE guidelines), have repeatedly been turned down by the US serum industry.

Wrong beliefs about risks associated to BSE have lead some FBS providers to promote the Australian origin as "safer" without any scientific basis, making this origin several times more expensive than any other. The Australia "safer" status is being promoted, despite the virus status of Australia (see FAQ #13); and despite the higher risk of misrepresentation associated with such huge price differences.

The price differences persist due to longtime marketing efforts promoting certain origins, and regulations limiting trade, even among countries that according to the OIE's classification have identical veterinary risk status (regarding viruses of import concern for FBS).  ISIA has among its objectives the education of serum users, and EU and USA are working to harmonize trade rules, all of which will contribute to harmonizing price levels for most FBS origins.

Why is FBS less expensive in Europe than in the USA?

FBS Imports into the EU are less restricted than in the USA. A proposal made by USDA in 1994 to apply the same FBS import policies as the EU did not get support from the US FBS industry. The International Serum Industry Association (ISIA) supports efforts to harmonize import rules, suggesting compliance with the OIE recommendations. In the meantime, FBS in the USA remains more than twice as expensive as in Europe.

What is FBS global supply?

The availability of FBS is diminishing. Meat and calf prices are increasing as consumers in some countries increase the consumption of beef; and as cattle breeding techniques are permanently improving. These combined factors lead to a reduced frequency of pregnant cows at slaughter. The collection of FBS in new countries has, for many years, compensated for the decrease in supply; but now there are no more new producer countries available. The present world supply of FBS is short and will continue decreasing.

Why is the demand for FBS increasing?

The demand for FBS is growing along with the latest research developments, including stem cells, cell therapy, new vaccines and proteomics.

Do I need to test FBS from Biowest?

Biowest FBS Premium has been especially selected to guarantee high performances and low batch to batch variations. You can save time by purchasing pretested FBS (See Catalogue Number S181B).

Is it necessary to heat inactivate serum?

For most cell culture applications, heat inactivation of serum is not recommended. Heat inactivation degrades complement proteins that may interfere with immunological assays. Heating serum for prolonged periods of time can reduce or destroy growth factors, as well as increase the formation of deposits which are commonly mistaken for microbial contamination.

How should the serum be heat inactivated?

  • Start by thawing the serum and the control serum bottle at 2-8°C.
  • Stir the bottled serum to avoid a precipitant from forming during the thawing, then place it in the water bath adjusted to 80°C.
  • Once the control bottle temperature reaches 50°C, adjust the bath thermostat to 70°C; when the bottle temperature reaches 55°C, change the thermostat to 60°C.
  • When the serum reaches the temperature of 56°C, use a timer (30 minutes is the registered time) and change the thermostat of the water bath to 56°C. During those 30 minutes, check the temperature regularly and maintain it stable by adjusting the thermostat, by adding some cold water, and by lowering the lid or not. Stir the serum every 5 to 10 minutes.
  • Keep the serum at room temperature for 30 minutes, and then freeze the serum at -20°C.

. The stirring is crucial for good serum quality. If the serum is not correctly mixed, a precipitant of salts, proteins and lipids will appear, and allow crystalline and flocculation deposits to form. These deposits are not toxic for cell culture but affect the serums appearance and consistency.
. Heating the serum for long periods can destroy the growth promoters, which can also enable deposits to form.

Why is FBS sometimes gamma irradiated?

FBS is sometimes gamma irradiated to eliminate all potential virus risks.

Does gamma irradiation affect FBS performances?

At standard dosage of gamma irradiation, no loss of performance is observed on the first generations of cells. We notice no change on hormones, osmolarity, pH, endotoxins nor electrophoretic profile of the FBS. As ionizing radiations kill viruses, it also break some proteins and decolorate the product by reducing haemoglobin level. Radiations also decrease the serum metabolites (ALP, ALT, AST, LDH) and may slightly affect growth promotion, plating efficiency and cloning efficiency with some cell lines.

Biowest suggests you to test your cell lines with serum gamma irradiated and not in order to define the potential impact of the treatment on your applications.

If viruses seem to modify the results of your work, Biowest also propose you to test FBS Biopharm, our highest quality, certified free of 11 major cattle viruses. 

What are the sampling rules for sterility tests on sera?

The sampling for sterility tests of all Biowest products conforms to the European Pharmacopeia requirements.

How are the samples tested for viruses?

Biowest tests the serum for the viruses (BVD, IBR, PI3) by using a cell culture method, so that live viruses, if present, are detected in the serum.

Why not use PCR testing for viruses?

A simple PCR test, not combined with the cell culture test, is used to detect DNA and RNA viruses that are alive and dead.

What is BSE?

Bovine spongiform encephalopathy (BSE), more commonly known as "mad cow" disease, is a fatal neurodegenerative disease (encephalopathy) in cattle.

What is the risk of BSE in serum products?

According to the OIE (World Animal Health Organization), there is no risk of BSE being transmitted in several products, including: milk, hides and skins, deboned meat, blood and blood by-products, such as fetal bovine serum (OIE Terrestrial Code 11.4 BSE). Most OIE member countries have adopted this position, including the European Union and the United States (USDA).

For some time, BSE was an argument used in favor of certain origins. After the OIE has determined that BSE is not transmitted by blood products, these arguments have become obsolete.

What makes Fetal Bovine Serum (FBS) unique?

FBS is essentially a natural product. All FBS batches are unique, with specific characteristics, different from all other batches.

Are there alternatives to FBS?

There are some cell lines specific serum-free alternatives available, including Biowest FreeAdd (Catalogue Number S6000). In most cases, cell adaptation is needed, yields are lower and costs are higher.

What is the recommended storage temperature for the serum?

The serum should be stored frozen and protected from light. The recommended storage temperature is -10°C to -40°C. At temperatures below -40°C, the bottles may become brittle increasing the risk of breakage.

How long can the serum be stored between +2 to +8°C?

Serum may be stored between +2 to +8°C for up to 8 weeks without diminishing its performance (*).
Internal studies in Biowest have shown that during 26 weeks of storage (between +2 and +8°C) the serum's capacity to promote cell growth was not significantly altered.
(*) Art to Science, Vol.19, No.2, "Serum Stability at Refrigerated Temperatures (2-8°C).

What are the deposits in the serum?

Turbidity and flocculent material may be present after thawing or after prolonged freezing and/or refrigeration. Our experience indicates these modifications do not affect the biological performance of the serum.

  • Some deposits are due to fibrin:

Our collection procedures and rapid freezing may leave some fibrinogen in the serum. Fibrinogen is the soluble precursor of the clot-forming protein, fibrin. The fibrin may appear after thawing or heat inactivation. Fibrin does not alter the capacity of the serum to promote cell growth. It is recommended to use the serum without treatment (filtration or centrifugation).

  • Some deposits are due to Calcium Phosphate:

Serum that is incubated at 37°C for extended periods will become cloudy and deposits may appear. They are composed of calcium and phosphorous. To the best of our knowledge, this does not alter the performance of the serum in cell cultures.

What is the best way to thaw serum?

Serum is thawed at 2-8°C to prevent degradation; alternatively, it may be thawed at room temperature with periodic agitation to resuspend the contents.

Thawed serum should be mixed thoroughly before being added to cell culture medium.

Temperatures above 37°C can compromise serum performance by accelerating the degradation of critical serum factors, and should be avoided in the lab.

Are Biowest products sterile?

Except where notified on product labels, Biowest sera and liquid media are sterile filtered. Sterility is not guaranteed after opening. The use of aseptic manipulation techniques is recommended.

How do I select FBS for stem cells?

In addition to normal testing, Biowest also tests FBS for stem cell work suitability. However, it is recommended that batches used for stem cells be tested on specific cell lines for the specific conditions required. Dr Yamanaka in his Nobel Prize winning work related to stem cell research, selected Biowest FBS after testing our batches.

Is it normal that the trypsin products do not always have the same color?

Some preparations of trypsin contain phenol red. Since the product is shipped with dry ice, there could be a significant CO2 build up in packaging. This CO2 may enter the solution and lower the pH slightly, giving an orange (around pH 6.5) vs. pinkish (around 7.3) color. The solution, if orange (acidic) can still be good to use as is, or sodium hydroxide may be added to adjust the pH.

Why is traceability important?

Traceability is important because it provides a chain of identity of the product from the country and slaughterhouse of origin, to the processing, packaging and labeling facilities ready for sale and final distribution. As you can verify, traceability insures that the product you buy was made respecting regulations at each level. This unbroken chain of information means complete transparency and entire compliance. 

How does Biowest guarantee traceability?

Biowest completely controls the supply chain from harvesting the raw material to filling sterile bottles.
Our traceability with SAP management software SAP Business One guarantees complete product traceability, from raw material until the end product. This software program plays a key role for achieving complete supply network traceability - enabling Biowest to determine batch lineage and global traceability.

What about animal welfare?

OIE's guidelines for animal welfare are respected in the countries where the FBS is collected (OIE Terrestrial Code 7.5 Slaughter of Animals).

Link to the EFSA explanation : EFSA explains animal welfare

Why kill pregnant animals?

The slaughtering of pregnant animals is, in most cases, an unplanned event. The frequency depends on farming techniques. In most cases, the condition of gestation is unknown; especially where animals are produced naturally; in the case of cattle moving freely around, grass fed, heifers and steers together. No cows are killed with the main purpose of harvesting the fetal blood. The blood is collected as a by-product from cattle slaughter operations for the bovine meat. The pregnancy condition is unknown when an animal enters the slaughtering line. The percentage of pregnant cows going to slaughter is very low and decreasing year by year as cattle farming techniques constantly improve.

Link to the EFSA explanation : EFSA explains animal welfare

Do the animals suffer?

The collection of the blood is done without causing pain to the fetus. The fetus's life ends through oxygen depletion, generally agreed to be a gentle method of life termination. Cell culture technology can reduce the use of live animals in science. Research is also being done to produce meat by cell culture, which could ultimately lead to the end of breeding animals for food.

Link to the EFSA explanation : EFSA explains animal welfare

What are the ethics?

Given that the death of some pregnant animals is unavoidable, the fetus can be used to serve science, and generate jobs. This contribution benefits research and development and should not be underestimated.

What about regulations and conformity?

Since the 1990s, from time to time, cases of illegal practices have been rumored. Only two cases are known to have been reported to authorities. In 2004, Biowest realized we had purchased and resold misrepresented origins; and in 2013, GE realized it had been selling misrepresented and adulterated FBS products, after acquiring the company PAA with activities in Austria, Canada and Australia. In both cases affected victims were informed, and product was recalled. Other cases are known to be under investigation. These cases illustrate the importance of having complete control of the supply chain.

What about misrepresentation and smuggling?

  • "Misrepresentation" is when the product is mislabeled in terms of the declared origin, and can be total or partial: "Total" is when FBS from a less expensive origin is sold as if it were from a more expensive origin; "Partial" is when a less expensive origin and a more expensive origin are mixed e.g. in proportion 49-51, and only the more expensive 51%- origin is declared. This generates an illicit profit for seller, at the expense of the serum users; and may cause companies to unknowingly violate import regulations or product master files. The actual research results and end products are unlikely to be seriously affected, but falsified origins violate government, industry and consumer standards of honesty and traceability.
  • "Smuggling" is a way of misrepresentation, and can be in the form of importing a product under a false description; directly to a final destination, or via third country.

What is adulteration?

  • "Adulteration" is the most damaging of the criminal activities that may affect serum users!

FBS can be adulterated by the addition of water, growth factors and/or serum of other species. Unscrupulous companies in order to enhance performance and/or lower the cost of the product can carry out one or more of these or similar activities. These practices are extremely serious as they affect critical results of life science research, and the purity of final products obtained in biopharmaceuticals, diagnostics, or vaccines. When such cases are detected, victims having used adulterated product must be informed to make it possible to evaluate the damage and take corrective actions.

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