A large proportion of immunology studies end up correlating a cellular measurement against a soluble one. Cytokine levels against T cell frequencies, autoantibody titre against B cell phenotype, metabolite concentration against monocyte activation. Those correlations only mean something when both measurements come from the same donor at the same draw, and that is precisely the thing most suppliers cannot provide.
The correlation you want to draw requires one donor and one draw
If PBMCs come from one donor cohort and plasma from another, the analysis can compare group means and nothing more. The moment the question becomes whether a soluble factor tracks a cellular phenotype within an individual, unmatched material stops being usable. That is a large fraction of biomarker work, most mechanism-of-action work, and nearly all of what pharmaceutical discovery groups actually want from disease-state material.
Matching also has to extend to the draw, not just the donor. Circulating cytokine levels, hormone levels and acute phase proteins vary day to day and, in some indications, within a day. Plasma from a donor’s second visit and cells from their first are only loosely matched, and the looseness lands in the residual variance.
What each fraction is actually good for
| Fraction | Carries | Typical use |
|---|---|---|
| Cryopreserved PBMCs | Lymphocytes, monocytes, dendritic and natural killer cells | Phenotyping, stimulation assays, signalling, sequencing |
| Plasma | Soluble proteins with clotting factors retained, anticoagulant present | Cytokine and chemokine panels, proteomics, metabolomics |
| Serum | Soluble proteins after clotting, platelet release products present | Autoantibody titres, most clinical chemistry, many validated immunoassays |
Plasma and serum are not interchangeable and the difference is not cosmetic. Clotting releases platelet contents into serum, which raises the measured level of several growth factors and chemokines substantially. An assay validated on serum will not necessarily give comparable numbers on plasma, and anticoagulant choice matters too. Deciding which fraction the assay needs before ordering avoids discovering the mismatch after the material is in the freezer.
Related product
Cryopreserved PBMCs. Single-donor PBMCs in current catalogue formats, with the donor record attached.
Why most suppliers cannot do this
The obstacle is operational rather than scientific. Supplying matched fractions requires that the collection, the aliquoting and the cryopreservation are controlled by the same organization, with a donor identifier that persists across all three products and documentation that ties them together at the lot level.
Where collection is contracted out and processing happens elsewhere, that chain breaks. The supplier can sell cells and can sell biofluids, and cannot reliably certify that a given vial of each came from one donor and one draw. OrganaBio operates its own apheresis collection through HemaCenter, its wholly owned apheresis collection subsidiary, and its own perinatal collection through GaiaGift, its wholly owned perinatal subsidiary, with processing in its own facilities. That is what makes matched sets deliverable rather than aspirational.
Where matched material changes the study design
- Biomarker qualification, where a candidate soluble marker has to be shown to track a cellular phenotype within individuals rather than across groups.
- Mechanism-of-action work, where a compound’s effect on cells is compared against the donor’s own circulating cytokine environment.
- Autoantibody-driven indications, where titre from the donor’s serum explains variation in their own B cell compartment.
- Assay bridging, where a new cellular assay is being compared against an established serological one on the same samples.
- Rare indications, where donors are scarce and obtaining several fraction types from each donor is the only way a small cohort supports a full panel.
Practical points when specifying a matched set
State the fractions required, the anticoagulant if the assay is sensitive to it, and the aliquot volume, because a matched set that arrives as a single large plasma aliquot will suffer freeze-thaw damage once it is subdivided. Small single-use aliquots are almost always the right choice for soluble analytes.
Record the draw date on all fractions and keep the donor identifier consistent across them in your own tracking, since that is the field the analysis will join on later. It is a trivial detail that is surprisingly often lost between receipt and analysis.
Availability and scope
Donor-matched plasma, serum and PBMCs are available from healthy donors and across the 24 autoimmune and inflammatory disease-state indications, subject to availability. Disease-state material is supplied for research use, covering discovery, drug screening and biomarker work, with a post-thaw viability specification above 80 percent on the cellular fraction.
Donor selection can be scoped by disease state, HLA genotype, age, sex, ethnicity, blood type, CMV and EBV status, BMI and smoking status, all subject to availability. High-resolution NGS HLA genotyping is performed across HLA-A, HLA-B, HLA-C, HLA-DR, HLA-DQ and HLA-DP, and KIR genotyping is included in donor characterization. Where a study needs the same donor sampled again later, the repeat-collection program covers eligible donors and is not a blanket guarantee for every donor or request.
Related material: what a mononuclear cell preparation contains, leukopak formats and specifications, and how HLA typing resolution is reported.
Frequently asked questions
Why can’t plasma and PBMCs be sourced from different suppliers?
They can, but the resulting data only supports group-level comparison. Any analysis correlating a soluble measurement against a cellular one within an individual requires both to come from the same donor and ideally the same draw.
Is plasma interchangeable with serum?
No. Clotting releases platelet contents into serum, raising measured levels of several growth factors and chemokines, and anticoagulant choice affects plasma assays. Match the fraction to what the assay was validated on.
Why is same-draw matching emphasised, not just same donor?
Circulating cytokines, hormones and acute phase proteins vary between days and sometimes within a day. Cells from one visit and plasma from another are only loosely matched, and that looseness shows up as residual variance.
What makes matched sets hard for other suppliers to provide?
It requires collection, aliquoting and cryopreservation under one organization with a donor identifier persisting across all products. Where collection is contracted out and processing happens elsewhere, the chain that certifies same-donor same-draw origin breaks.
How should aliquot size be specified?
Small single-use aliquots are almost always right for soluble analytes, because a single large aliquot has to be subdivided and will take freeze-thaw damage. State aliquot volume when ordering rather than accepting a default.
Are matched sets available for disease-state donors?
Yes, across the 24 autoimmune and inflammatory indications as well as healthy donors, subject to availability. Disease-state material is research use only, with a post-thaw viability specification above 80 percent on the cellular fraction.
Is this material suitable for clinical manufacturing?
Disease-state material is research use only. Material intended for further manufacturing is a separate cGMP scope with its own agreement and documentation requirements.
What viability specification applies to this material?
Disease-state donor material carries a post-thaw viability specification above 80 percent. That figure applies to the disease-state line specifically and is not carried across from healthy donor products.
Can this material be used for clinical manufacturing?
No. Disease-state donor material is supplied for research use covering discovery, drug screening and biomarker work. Material intended for further manufacturing is a separate cGMP scope with its own agreement and documentation requirements.
Talk to OrganaBio
Need this material for a specific process?
Formats, vial sizes and donor characterization vary by product, and custom formats are documented where a process needs them. Tell us what your process requires and the scientific team will confirm what can be supplied.
