Leukopaks: Fresh, Split and Cryopreserved

Why choose our leukopaks

• High cell concentration: fresh leukopaks contain at least 40 × 10⁹ leukocytes/L.
• Full blood profile with every leukopak: haemoglobin, haematocrit, complete blood count, lymphocyte and monocyte counts, and cell concentration.
• High cell purity: low haemoglobin and haematocrit.
• Screened donors: every donor has a medical examination and has given plasma before. Every donation is tested against a full viral-marker panel.
• Reliable supply: donor networks in the United States and Europe. Recall donors are available on request, and a backup donor is booked for every collection.
• Audited collection: collection centres are audited by the EMA and FDA and work to GMP protocols and validated SOPs. Every step is traceable, from donor eligibility through to delivery.

Choosing a format

Fresh leukopaks ship cold at +2°C to +8°C within 24 hours of collection. Choose fresh when you need high-viability cells and can process them straight away. They come as full or half leukopaks. Research-use-only grade is standard, and GMP grade is available on request. Split leukopaks are fresh leukopaks divided into two equal units at the point of collection, using sterile welding and validated bags. Each unit has the same cell populations and concentration, and each can go to a different address. That makes them a good fit for multi-site studies, technology transfer, validation and proficiency testing. Custom fill sizes and extra splits are available on request. Cryopreserved leukopaks are frozen using a controlled-rate process and ship on dry ice. Post-thaw viability is at least 90% and recovery is at least 80%. They come in 50 mL quarter cryobags of about 2.5 × 10⁹ cells. A full leukopak gives 3 to 6 bags from one donor, with a minimum of 3. Store at -80°C. Donor documentation covers age, gender, race, blood type and viral screening records.

Applications

• Cell therapy research and process development, including CAR-T, stem cell and immunotherapy workflows
• Assay development, validation and proficiency testing
• Multi-site and comparative studies using material from the same donor
• Longitudinal and stability studies using repeat donors
• Flexible study scheduling with cryopreserved stock

Custom donor requirements

We can source HLA-matched, recallable and specified donors, for example by age, BMI or ethnicity. Immunophenotyping (CD3, CD4, CD8, CD14, CD19, CD56) is also available. These options may carry an extra charge and depend on donor availability. Contact our team at sales@lifesciencegroup.co.uk.

Frequently asked questions

What is a leukopak?

A leukopak is an enriched leukapheresis product collected from a single donor using a closed-loop system. It contains a high concentration of mononuclear cells, mainly lymphocytes and monocytes.

How many cells are in a leukopak?

Fresh leukopaks are specified at a concentration of at least 40 × 10⁹ cells/L. This is not a guaranteed total cell count. Full fresh leukopaks contain at least 10 × 10⁹ cells and half leukopaks at least 5 × 10⁹. Cryopreserved quarter bags target 2.5 × 10⁹ cells (±10%).

What grades are available?

Research-use-only grade is available in every format. GMP grade fresh leukopaks are available on request.

What virology testing is carried out?

Every donation is tested for HIV, HBV and HCV by NAT and serology, plus HTLV I/II, HAV, HEV, parvovirus B19, West Nile virus, syphilis and Chagas. Panels depend on regional and regulatory requirements.

Can I select donors by HLA type?

Yes. Send us your HLA requirements and we will search the donor database for a match before collection. HLA matching is specific to each customer, so there is no standard loci panel or typing resolution. It is chargeable and depends on donor availability.

How are leukopaks shipped and stored?

Fresh leukopaks ship at +2°C to +8°C within 24 hours of collection. Cryopreserved leukopaks ship on dry ice and should be stored at -80°C for the long term.