Blood Samples for Research: PBMCs, Leukopaks, Plasma & More

High-quality blood biospecimens are fundamental to progress in biomedical research, supporting advancements in immunology, haematology, regenerative medicine, and drug discovery. Choosing the right type of blood-derived sample is essential, as each offers unique characteristics suited to specific experimental needs.

In this guide, we outline the main types of healthy blood biospecimens and their key applications in modern research.

Whole Blood for Research

Collection method:
Whole blood is collected directly from donors into tubes or bags containing anticoagulants to prevent clotting.

Key characteristics:
It includes all primary blood components—plasma, red blood cells (RBCs), white blood cells (WBCs), and platelets.

Applications:

• Development and validation of diagnostic devices (e.g., blood glucose testing systems and point-of-care diagnostics)
• Coagulation and thrombosis research, including evaluation of clotting disorders and anticoagulant therapies
• Studies of inflammation, immune response, and infectious diseases, including cytokine profiling

Leukopaks

Collection method:
Leukopaks are produced using apheresis, a technique that isolates and concentrates leukocytes from donor blood.

Key characteristics:
They provide a high yield of peripheral blood mononuclear cells (PBMCs), including T cells, B cells, monocytes, and natural killer (NK) cells.

Applications:

• Large-scale immunology research requiring significant numbers of immune cells
• Immunotherapy development, including CAR-T cell therapies and checkpoint inhibitors
• Vaccine research focused on adaptive immune mechanisms

Peripheral Blood Mononuclear Cells (PBMCs)

Collection method:
PBMCs are isolated using density gradient centrifugation (such as Ficoll-Paque) from sources like whole blood, leukopaks, or buffy coats.

Key characteristics:
They are enriched in lymphocytes and monocytes, making them essential for immune-based analyses.

Applications:

• T-cell activation studies, cytokine release assays, and autoimmune disease research
• Development and testing of immunotherapies
• Regenerative medicine, toxicology studies, and drug response evaluation

Buffy Coat

Collection method:
The buffy coat layer is obtained by centrifuging anticoagulated whole blood, separating it from plasma and red blood cells.

Key characteristics:
It contains a dense concentration of white blood cells, including granulocytes and PBMCs.

Applications:

• Cost-effective isolation of PBMCs for immune assays and biomarker discovery
• Genomic and transcriptomic research, including DNA and RNA extraction
• Infectious disease studies such as HIV and tuberculosis research

Leukocyte Reduction Cones

Collection method:
Leukocytes are captured during routine blood or platelet donation through in-line filtration systems.

Key characteristics:
They offer a readily available and economical source of PBMCs, though they contain few or no granulocytes.

Applications:

• Functional assays to study immune cell activation and cytokine production
• Cell culture and drug screening workflows
• Suitable for laboratories needing a consistent and accessible source of white blood cells
  Note: Manual extraction from filters may lead to partial cell activation due to mechanical stress.

Plasma

Collection method:
Plasma is separated from anticoagulated whole blood through centrifugation to remove cellular components.

Key characteristics:
It is rich in proteins, clotting factors, and metabolites, making it highly valuable for analytical studies.

Applications:

• Proteomics, metabolomics, and pharmacokinetic studies
• Biomarker discovery and toxicology research
• Exosome and extracellular vesicle analysis, including liquid biopsy applications

Serum

Collection method:
Serum is obtained after allowing blood to clot, followed by centrifugation to remove cells and clotting proteins.

Key characteristics:
It lacks fibrinogen but contains antibodies, cytokines, and a wide range of biomolecules.

Applications:

• Supplement in cell culture media to support cell growth and viability
• Standard matrix for validating diagnostic assays
• Serological testing and antibody-based studies, including vaccine and infectious disease research

Red Blood Cells (RBCs)

Collection method:
RBCs are isolated from whole blood via centrifugation, separating them from plasma and leukocytes.

Key characteristics:
They are haemoglobin-rich cells responsible for oxygen transport, widely used in haematology.

Applications:

• Research into anaemia, sickle cell disease, and erythropoiesis
• Malaria studies, as Plasmodium parasites infect RBCs
• Investigation of virus interactions with red blood cells

Isolated Immune Cells

Collection method:
Specific immune cell populations are purified using immunomagnetic separation, often from leukopaks.

Key characteristics:
Highly purified cell subsets such as T cells, B cells, and NK cells enable precise experimental targeting.

Applications:

• Development of advanced immunotherapies, including CAR-T and CAR-NK cell therapies
• Immune toxicity and cytokine release studies
• High-throughput drug screening targeting specific immune pathways

Conclusion

Reliable access to high-quality blood biospecimens is critical for advancing life sciences research. Selecting the appropriate sample—whether whole blood, PBMCs, plasma, or specialised immune cells—helps optimise study design and improves experimental outcomes.

These biospecimens continue to drive innovation across immunology, oncology, haematology, and regenerative medicine.

Find the Right Blood Biospecimen for Your Research

Choosing the correct blood product can significantly impact your results. Explore the options available and select the biospecimen that aligns with your research goals to accelerate discovery and development.