While convenient for logistics, this delay is detrimental to T-cell biology. Research published in the Journal of Immunological Methods consistently shows that granulocyte contamination increases significantly after 24 hours in ambient blood.
The Biology of Delay
As blood sits in transit, granulocytes (neutrophils) change density. When processed the next day, these activated neutrophils co-purify with the PBMC layer.
These contaminants release enzymes that can cleave surface receptors on T-cells and suppress cytokine secretion. This leads to suppressed immune responses in ELISpot and Flow Cytometry assays—essentially, the data looks negative even if the patient is responding. Ultimately, this leads to unusable datasets following expensive assays and readouts.
Accelevir’s Same-Day Infrastructure
For clinical sites that demand the highest quality data, Accelevir offers a comprehensive Same-Day First Morning PBMC Processing Service.
By processing blood within hours of the draw:
- Maximize Recovery: We capture the cells before granulocytes become an issue.
- Preserve Function: The cells are cryopreserved in their optimal “in vivo” state.
- Standardize Data: We remove the variable of “shipping stress” from your dataset.
Conclusion
Logistics should not compromise science. If your trial endpoints depend on sensitive T-cell measurements, the “24-Hour Cliff” is a risk you cannot afford to take.

