The actin story
Every cell that migrates — endothelial cells sealing a wound, fibroblasts entering a lesion, myocytes reorganising after strain — depends on rapid, controlled polymerisation of actin. Thymosin β4 is the master regulator of the free actin pool.
TB-500 replicates the active region of that protein, giving researchers a defined molecular tool for studying migration-dependent processes without introducing the full protein and its confounding interactions.
Why the fragment, not the parent
The 17-residue active fragment is cheaper to synthesise reproducibly, easier to characterise, and produces cleaner dose-response curves. In most migration and angiogenesis assays it behaves indistinguishably from full-length thymosin β4.
Downstream vascular effects
Beyond migration, TB-500 upregulates endothelial cell differentiation and appears to modulate inflammatory signalling. In cardiac injury models it consistently improves both structural and functional endpoints, which is why it has become a reference instrument in regeneration research.
Handling
Store lyophilized TB-500 at −20 °C. Reconstitute in bacteriostatic water; avoid vortexing at high speed, which can shear the peptide. Use reconstituted material within the window validated by the receiving laboratory.