Human AB Serum

Why male-only human AB serum?

Human AB serum is widely used as a xeno-free alternative to foetal bovine serum (FBS) for culturing sensitive human cells in research and manufacturing. Serum from blood group AB donors contains no antibodies against the A and B blood-group antigens, so it is the standard choice when you need to keep immune reactivity to a minimum.

Male-only serum goes a step further. Women who have been pregnant can develop antibodies against major histocompatibility complex (MHC) antigens from the father or foetus. Using male donors only removes that risk, which is why male-only AB serum is preferred for immune cell and cell therapy work.

Applications

Human serum gives human cells a more natural environment than animal sera such as FBS. It is the serum of choice for immune cells such as lymphocytes and macrophages, and may be needed to meet regulatory expectations on animal-derived materials.

• Expansion of mesenchymal stem cells from adipose tissue, and mesenchymal stromal cells from bone marrow, for cell therapy and transplantation
• Ex vivo expansion of NK cells from peripheral blood
• T cell and CAR-T cell culture
• Pre-transplant human islet culture
• Tissue engineering, including limbal epithelial stem cell grafts
• Antibody-based HLA tissue typing, serological typing and as a blocking agent
• Routine culture of human cell lines

Choose the right human AB serum

Option	What it means	Best for
Off the clot (OTC)	Whole blood is allowed to clot naturally and the serum is collected. A richer, more varied growth factor profile, and the closest to native human serum	Applications where performance closest to normal human serum matters most
Converted (plasma-derived)	Pooled plasma, collected by plasmapheresis, is defibrinated with thrombin or calcium. Plasma donors are usually regular, long-term donors who are closely monitored	Large-scale manufacturing, consistent large lots and lower cost
Xeno-free converted	Converted using recombinant human thrombin instead of bovine thrombin	Processes that must avoid all animal-derived materials
Research grade	Suitable for research use	Research and development
cGMP grade	Manufactured in a cGMP-certified facility, in batches of 1–250 litres, for full traceability and quality control	Further manufacturing, cell therapy and clinical applications
US origin	Collected at FDA-licensed facilities	Programmes that need FDA-licensed sourcing
EU origin	Collected at EU-registered facilities	Programmes that prefer EU-sourced material

Off-the-clot batches are typically pooled from 200–250 pre-screened donors, with no more than 300 donors per pool. Plasma for converted serum is collected into 4% sodium citrate by automated plasmapheresis at FDA-licensed facilities, which helps keep batch-to-batch variation low.

Quality and testing

• US origin: collected from healthy male AB donors at FDA-licensed facilities, in line with 21 CFR 640 subpart G. Every donor unit is tested to 21 CFR 610.40 and found non-reactive for HBsAg, HIV-1/2, HCV and syphilis using FDA-approved methods. The final pool is also tested for HCV RNA, HBV DNA, HTLV-1/2 and HIV-1 RNA, with further testing for West Nile virus and Chagas disease.
• EU origin: collected from healthy male AB donors at EU-registered facilities. All units are non-reactive for HBsAg, HIV-1/2, HCV RNA, HTLV-1/2, HIV-1 RNA and syphilis.
• Sterility: sterile filtered to 0.1 µm and tested for the absence of bacteria, fungi, yeast and mycoplasma.
• BSE/TSE: free from BSE and TSE with respect to source, manufacture and treatment. Donors at potential risk of TSE transmission are excluded by a qualified medical practitioner.
• Further manufacturing: additional viral testing is available to meet current regulatory standards.

What to look for when choosing a batch

• Traceability: serum from licensed, reputable collection facilities, such as FDA-licensed centres in the US
• Donor profile: male-only AB donors; younger donors (typically under 35) tend to give serum with higher growth potential
• Endotoxin: low endotoxin, tested by LAL, supports healthy cell growth
• Haemoglobin: high free haemoglobin can signal poor processing and may be toxic to sensitive cells
• Lot-to-lot consistency: test a sample and reserve a batch for long-term projects

Treatments, formats and custom manufacture

• Treatments: available heat inactivated (typically 56 °C for 30 minutes, to destroy complement activity), gamma irradiated, charcoal stripped or dialysed
• Bottles: standard 100 mL fill in 125 mL bottles. Smaller volumes such as 25 mL and 50 mL, single-dose bags and bottles with septum caps are available on request
• Closed-system bags: selected cGMP products come in 750 mL Aseptic Assurance System™ cryo-bags made of EVA film. The bags drain completely, withstand storage down to -196 °C and thawing at 37 °C, and have weldable tubing (about 14 cm) and two spike ports with twist-off caps for sterile connection to closed systems
• Custom manufacture: custom fill sizes and packaging, added supplements such as growth factors and cytokines, or complete media containing human serum made to your formulation through our custom manufacturing service

Samples and batch reservation

Samples of around 25 mL are available so you can test a batch before you buy. We hold batch reservations for four weeks while you evaluate.

Storage, shelf life and handling

Store at -20 °C or below and protect from light. Human AB serum ships frozen on dry ice and typically has a shelf life of five years from manufacture. If long shelf life matters, ask us about the expiry of the batch you are considering.

Avoid repeated freeze–thaw cycles. Thaw under controlled conditions and re-aliquot into smaller volumes before re-freezing. Don’t store or refreeze partially used serum, as it degrades quickly if contaminated. Handle all human-derived material as potentially infectious, using universal precautions.

Request a quote or a sample at sales@lifesciencegroup.co.uk or on +44 1234 889180.

Frequently asked questions

Why use AB serum rather than another blood type?

Serum from blood group AB donors contains no anti-A or anti-B antibodies, so it won’t react with A or B antigens on cultured human cells.

Why male donors only?

Women who have been pregnant can carry antibodies against MHC antigens. Male-only serum removes that risk, which matters for immune cell and cell therapy applications.

What is the difference between off-the-clot and converted human AB serum?

Off-the-clot serum comes from whole blood that is allowed to clot naturally, giving a growth factor profile closest to native serum. Converted serum is made by defibrinating pooled plasma. It suits large-scale manufacturing and gives consistent, cost-effective lots.

Is xeno-free human AB serum available?

Yes. Our xeno-free cGMP serum is converted using recombinant human thrombin rather than bovine thrombin, so no animal-derived materials are used.

Do I need heat-inactivated serum?

Heat inactivation, typically 56 °C for 30 minutes, destroys complement activity that can interfere with cell growth or some assays. It is optional, and both heat-inactivated and non-heat-inactivated versions are available.

Can I test a batch before ordering?

Yes. We can send a sample of around 25 mL and hold a batch reservation for four weeks while you evaluate it.

How long does human AB serum last?

Typically five years from manufacture when stored at -20 °C or below and protected from light. Ask us for the expiry of a specific batch.