Frequently Asked Questions
What is the level of growth factors in Fetal Bovine Serum, Product F2442?
Sigma Aldrich does not determine the levels of growth factors (such as TGF beta, VEGF, EGF, PDGF, or FGF) for serum with reduced levels of growth factors and plasma derived serum.
Is Fetal Bovine Serum, Product F2442, available as a charcoal stripped, de-lipidated serum?
We offer Product No. F6765 (Fetal Bovine Serum, charcoal stripped). The charcoal stripping decreases the levels of hormones; it may also decrease the levels of lipids. If further reduction of lipid levels is required, you may need to treat the serum with fumed silica (e.g. Product No. S5130). Use 20 grams of S5130 per Liter of serum (not plasma). It is mixed for 3-4 hours, then centrifuged in 1 L containers for about 15 minutes at 2000 xg. The supernatant can then be decanted, and filtered if desired. NOTE: Silica is extremely fluffy, and care must be taken not to inhale its dust. Allow for about 15% loss of the serum due to adsorption.
How is Fetal Bovine Serum, Product F2442, cell culture tested?
Biological performance is assessed using Sigma cell culture medium supplemented with the serum and tested at a final concentration of 10%. Seeding efficiency, doubling time, and final cell density are measured on appropriate cell lines. Growth studies are carried through two subculture generations and cell growth is plotted as a logarithmic function of time in culture. During the testing period, cultures are examined microscopically for atypical morphology and evidence of cytotoxicity. Hybridoma -tested serum has been shown to support mouse myeloma cells and hybridoma cells in culture.
What is the cloning assay performed on Fetal Bovine Serum, Product F2442?
The cloning efficiency assay is performed on each lot of FBS to verify that each lot will support clonal growth of myeloma cells and/or fusion products. The assay is performed using 5% and 10% concentrations of the FBS.
What is the difference between Fetal Bovine Serum F2442 and 12103C?
Product No. 12103C meets most of the specifications of F2442. Both products are from the same raw material suppliers and undergo the same stringent testing prior to release. However, the F2442 has been use-tested in hybridoma culture, whereas 12103C has not.
Which document(s) contains shelf-life or expiration date information for a given product?
If available for a given product, the recommended re-test date or the expiration date can be found on the Certificate of Analysis. These documents are located on the product detail page under Useful Links & Tools. Click on the following link to search for a Certificate of Analysis.
Please click the following link to see the details on our Product Dating Information.
Are all Fetal Bovine Serum (FBS) products heat inactivated?
Not all Fetal Bovine Serum products are heat inactivated. Product numbers F4135 and 12306C are heat-inactivated FBS.
There is a precipitate in my serum. Is my serum contaminated?
Precipitates in serum can often appear as large round bodies, even as doublets per microscopic exam. This can be mistaken as a yeast contamination. Brownian motion may be mistaken for motility. These are lipid aggregates that will be readily dissolved when exposed to lipase. Also, these particles will not gram stain or show any growth in culture on aerobic, anaerobic, or fungal media and culture conditions. The performance of the material is not effected. Centrifugation or filtration of small volumes will remove these particles.
How do I get lot-specific information or a Certificate of Analysis?
A Certificate of Analysis is available by lot number and can be obtained through our Advanced Search Option: http://www.sigmaaldrich.com/catalog/AdvancedSearchPage.do
How do I find price and availability?
There are several ways to find pricing and availability for our products.
Once you log onto our website, you will find the price and availability displayed on the product detail page.
You can contact any of our Customer Sales and Service offices to receive a quote. USA customers: 1-800-325-3010 or view local office numbers.
What is the Department of Transportation shipping information for this product?
Transportation information can be found in Section 14 of the product's (M)SDS.
To access the shipping information for this material, use the link on the product detail page for the product, or search here.
My question is not addressed here, how can I contact Technical Service for assistance?
Use the option to the right to "Ask a Question" by email of a Technical Service Scientist.
Does Sigma-Aldrich offer delipidated bovine serum?
At this time, Sigma-Aldrich does not offer delipidated bovine serum (either FBS or calf serum).
A method for lipid depletion, though not necessarily that of Sigma:
1. While mixing, gradually add 10 g fumed silica (Product S5130 or Aerosil) per liter of serum
2. Mix at room temperature and then transfer to 2-8 °C for overnight mixing.
3. After overnight mixing, remove flumed silica (Aerosil) by centrifugation at 3000-5000 rpm for 5 minutes.
4. Retain the supernatant. The lipids should stick to the silica. There may be some protein loss
Does Sigma-Aldrich offer fetal bovine serum (FBS) that is antibiotic-free?
FBS can be tested for the presence of antibiotics. Products F2442, F0926, and F6178, Fetal Bovine Serum are routinely tested for Tetracycline (by far the most commonly used antibiotic in animals) and the results are reported on the lot specific Certificate of Analysis.
Per the USDA, Antibiotics may be given to prevent or treat disease in cattle. A "withdrawal" period is required from the time antibiotics are administered until it is legal to slaughter the animal. This is so residues can exit the animal's system. FSIS randomly samples cattle at slaughter and tests for residues. Data from this Monitoring Plan have shown a very low percentage of residue violations.
The USDA does random sampling of all cattle submitted for slaughter in USDA inspected facilities for antibiotics. The mandatory withdrawal period is 24 hours. Based on withdrawal periods required by the USDA, animal testing at slaughter and finished product testing, our serum is antibiotic free.
Once a bottle of Fetal Bovine Serum (FBS) is thawed, for how long can the bottle be used?
Once Fetal Bovine Serum has been thawed, the bottle can be used in cell culture for up to 7 days for most cell types when stored refrigerated at 2-8°C. If the cells are not fastidous (e.g. HeLa or fibroblasts), the thawed and refrigerated serum can be used for up to 30 days. For some extremely fastidious cell lines, it may be necessary to screen individual lots for acceptable performance. For uses such as blocking for various immuno procedures, usage will generally be for 30 days and perhaps somewhat longer when stored at 2-8°C. For other procedures, usage beyond 30 days storage at 2-8°C will need to be determined.
What kind of solution is the A5955 - Antibiotic Antimycotic Solution (100×), Stabilized product suspended in?
A5955 - Antibiotic Antimycotic Solution (100×), Stabilized is supsended in a sodium citrate buffer solution.
Source: Israel production group