HUMAN AB SERUM FAQ
Most Frequently Asked Questions and Answers About Human AB Serum
Although it is impossible to claim stability data for every possible application and use, for human serum AB we conservatively estimate that if this product is stored properly at -20ºC, it can be used up to 5 years from the date of manufacture without any decrease in product performance. Storage at any other temperature may affect results. However, once thawed and opened for use, it is not recommended to store or refreeze partially used serum as degradation is rapid if microbial contamination occurs.
Human AB Serum is a vital cell culture reagent for some human cell types providing growth factors, vitamins, nutrients as well as trace elements and transport factors, ensuring faster growth rates than mixed blood group serum. Human AB is proven to grow many human cell lines at a faster rate and with a smaller percentage of serum than mixed blood group serum.
US origin
Human AB serum is collected from healthy volunteer male donors of the AB serotype at FDA-licensed facilities in the United States and collected in compliance with health requirements established by 21CFR 640, subpart G.
The converted serum is routinely screened for the presence of animal contaminants. This is performed by DNA analysis.
French origin
Human AB serum is collected from healthy volunteer male donors of the AB serotype at EU-registered facilities. The material is CE-marked and ANSM-approved IVDMD. Please note that in France some donations are made for purely non-therapeutic purposes. In these cases, the age of the donors can be significantly higher than standard donations and also transplanted/transfused donors may be selected to donate.
No animal-derived ingredients (ADI) are used in the production of French-origin Human AB serum. The manufacturing process does not use any ingredient of animal origin.
Each lot of human serum type AB of clot typically derives from 200-250 pre-screened donors. Smaller batches may be made available to a specific number of individual donors. Batches of Human AB serum from converted plasma may be constructed to have a smaller number of donors, potentially 10-15, and be reproducible.
Women who have been pregnant may develop antibodies against major histocompatibility class (MHC) antigens carried on the father’s cells and/or the foetus’ cells. Male donors present no such risks.
Human serum from type AB donors lacks antibodies against the A and B blood-type antigens and is therefore commonly used when there is the need to minimize immunoreactivity.
The off-the-clot serum is collected from the blood that is allowed to coagulate naturally after collection. It has not been exposed to any anticoagulant. The plasma-derived serum is produced by defibrinating pooled human blood collected in the presence of bovine thrombin. The plasma-derived serum is generally more economical and popular than the off-the-clot product. Both Off-the-clot serum and plasma-derived serum are available in both pooled lots and individual transfer packs from specific donors.
Human AB serum supplied by LSG is suitable for research, diagnostic and further manufacturing purposes. Full details as to the collection and processing of human AB serum are available on request. Specific batches of serum may be subjected to additional viral testing, as required. LSG is very happy to discuss specific batch and collection requirements to meet individual regulatory requirements.
Human AB may be supplied in any bottle size e.g. 1 litre, 500 mL, 100 mL, 50 mL, 25 mL, as required, including bottles fitted with septums for the aseptic removal of serum. Human AB serum may also be processed into single-use bags with tubing sets to meet individual production requirements.
Recommended storage is -20°C or below.
Protect serum from exposure to light.
It is recommended to avoid freeze-thaw cycles as this can lead to a deterioration in serum qualities. Ideally, material should be thawed under controlled conditions and re-aliquoted into smaller volumes before re-freezing. It is not recommended to store or refreeze partially used serum as degradation is rapid if microbial contamination occurs. All biological material should be handled as potentially infectious. It is essential that universal precautions should be employed when handling Human AB serum.
Manufacturing grade Human AB serum offers enhanced donor traceability and additional viral testing compared with standard grade.
Each batch of Human AB serum is tested to ensure freedom from bacteria, fungi, yeast, and mycoplasma (M. pneumonia, M. hominis and M. salivarium). Batches are also tested for the ability to support the growth of specific cell lines. In addition, each batch is also tested for standard parameters. These include endotoxin, pH, osmolality, protein content, albumin, IgG and haemoglobin levels. Details for each batch are supplied on the Certificate of Analysis (COA).
All donor units that form each batch are tested for HBsAg, anti-HCV, anti-HIV1 and 2, HIV-1, and Syphilis. Additional viral testing on both individual donors and pooled material is available to meet current regulatory standards for further manufacturing.
Each batch of Human AB serum is tested for the absence of bacteria, fungi, yeast, and mycoplasma. Our Human AB serum is also sterile filtered to either 0.1 µm pore size-rated filters (US Origin) or 0.2 µm pore size-rated filters (French Origin). Results of microbe testing of each batch of serum are supplied in the COA. However, please note that sterility is not guaranteed after opening. The use of aseptic techniques during handling is recommended.
Yes. Human AB serum is available as heat-inactivated, gamma-irradiated, dialysed and charcoal-stripped material.
Human AB Serum may be heat inactivated by heating to 56°C for 30 minutes to inactivate various components in the serum such as complement factors.
At one time, heat inactivation was considered necessary because of concerns over the presence of contaminants in serum. However, the process of heat inactivation is known to degrade valuable biomolecules, such as growth factors, vitamins, and amino acids. Many protocols still call for the serum to be subjected to heat treatment prior to use without consideration as to whether it remains desirable. Should it be required, LSP can provide heat inactivation as a custom processing option.
Yes. We offer samples of Human AB Serum for testing prior to the selection of a suitable batch. The typical sample size is 25 mL and reservations are held for a period of four weeks, pending evaluation.
Human AB Serum has a shelf life of 5 years from the date of manufacture, provided it is stored appropriately. We would recommend enquiring about the shelf life of each available batch if it is important to have a long shelf life following purchase.
Despite all testing, proper safety precautions for potentially infectious agents must be taken. All human blood products should be handled in accordance with currently acceptable bio-safety practices and guidelines for the prevention of blood-borne viral infections.
US Origin
The deferral time for any transfusion patient to stop donating blood products is 12 months. After this time, these donors can return to donating blood, serum or plasma. Transfusion grade collections don’t allow for transfused patients to donate. However, only some sites collect “transfusion grade” serum while others don’t. This means that blood from transfused patients can be present in material pooled from a number of different sites.
EU Origin
In France, it is permitted for people who have received blood transfusions to donate blood for non-therapeutic applications
HLA antibodies are not naturally occurring and can only be acquired by pregnancy, transfusion of blood products or transplantation. Therefore, for a donor pool of un-transfused male donors with blood group AB, provided the donors are healthy, you can expect a very low incidence of HLA antibodies.
Depending on your specific application, you would need to use serum from non-transfused patients if it is important that the serum you receive is HLA free.
Also see the question: Can donors who have received blood transfusions, donate blood for Human AB Serum collection purposes?
Human AB serum will be shipped frozen, by overnight courier in polystyrene moulded boxes with dry ice unless we are specifically requested not to do so. This will ensure that the material arrives frozen in good condition.
LSP goes to great lengths to ensure that our human sera are the most consistent products commercially available. Although our human serum is manufactured using raw material from congruous donor pools and according to time-tested protocols, it is possible to perceive differences in the physical appearance of this product from lot-to-lot. This phenomenon can be largely attributed to variation in diet amongst human beings (particularly with respect to dietary fats). Another source for slight differences comes from non-uniform storage conditions and/or handling variations in the laboratory setting. Due to the special sensitivity of this product (as compared to other sera), it is critical that human serum be cared for as recommended by the manufacturer.
When serum is thawed, some precipitation may be seen. This is a normal phenomenon and it does not compromise the quality of serum in any way. To remove the precipitate, transfer the serum to sterile tubes and centrifuge for 5 mins at 400g.
To limit the amount of precipitation, we recommend that the serum is thawed in a refrigerator at 2-8°C. The serum should be regularly mixed during this process.
In the unusual event of serum arriving partially thawed, please note that it is inadvisable to refreeze from this state as partially thawed serum must be allowed to thaw completely at 4°C.
When the serum has thawed completely, gently invert the container several times to achieve thorough mixing and refreeze as soon as possible to -20°C. To avoid repeated freeze/thaw cycles dispense the serum into single use aliquots before freezing.
Although it is impossible to claim stability data for every possible application and use, for human serum AB we conservatively estimate that if this product is stored properly at -20ºC, it can be used up to 5 years from the date of manufacture without any decrease in product performance. Storage at any other temperature may affect results. However, once thawed and opened for use, it is not recommended to store or refreeze partially used serum as degradation is rapid if microbial contamination occurs.