What is Human Platelet Lysate (hPL)

How is hPL made?

Platelets are collected from screened human donors via apheresis or whole blood donation. The platelet concentrate is subjected to 3–5 freeze-thaw cycles (typically −80°C → 37°C), which ruptures platelet cell membranes and releases intracellular contents — including dense granules (ADP, serotonin, calcium), alpha granules (PDGF, TGF-β, EGF, vWF, fibronectin), and lysosomal contents — into the surrounding plasma. The lysate is then filtered (0.2 µm) and pooled from multiple donors to reduce lot-to-lot variability.

hPL vs FBS — key differences

Unlike FBS, hPL provides human-sequence growth factors that are species-matched for human cell culture. For MSCs, fibroblasts, endothelial cells and other primary human cells, human growth factor receptor binding is more efficient with human-sequence ligands than with bovine FBS equivalents. This explains why hPL at 5% often achieves higher proliferation rates than FBS at 10% for human cell types.

When to use hPL instead of FBS

Use hPL for: MSC expansion (bone marrow, adipose, umbilical cord), primary human fibroblasts, endothelial cells, keratinocytes, CAR-T and NK cell manufacturing, and any xeno-free ATMP protocol. Keep FBS for: rodent cell lines, hybridoma culture, standard cancer cell lines, and viral vector production.

Key Facts

• hPL is produced by 3–5 freeze-thaw cycles of pooled human platelet concentrates from screened blood donors
• Growth factor content is 10–50× higher than standard FBS — particularly PDGF-AB, PDGF-BB, TGF-β1, and IGF-1
• hPL at 5% frequently outperforms FBS at 10% for MSC proliferation rate and population doubling time
• Xeno-free: no bovine components — suitable for ATMP manufacturing and clinical-grade human cell therapy production
• Contains fibrinogen — add heparin (2 IU/mL) to prevent gel formation, or use fibrinogen-depleted formulations
• NOT suitable for hybridoma culture — human IgG (8–12 mg/mL) co-purifies with murine mAb during Protein A/G chromatography
• GMP-grade formulations available with full blood bank donor documentation

Further Reading

• hPL Complete Guide — When & How to Switch from FBS
• What is Off-the-Clot Serum?
• Serum-Free Adaptation Protocol
• iPSC & Stem Cell Culture Guide

SeamlessBio GmbH · Passau, Germany · info@seamlessbio.de · +49 851 37932226