What Is TB-500 (Thymosin Beta-4)?
A 43-amino-acid actin-sequestering protein studied in cell-migration and angiogenesis models. Structure, identifiers, handling, and what the literature measures.
Identity
TB-500 is the synthetic form of Thymosin Beta-4, a naturally occurring 43-amino-acid protein. Its best-characterised biochemical property is binding monomeric (G-) actin, which is why the literature classes it as an actin-sequestering protein rather than a signalling peptide.
| CAS number | 77591-33-4 |
|---|---|
| Molecular formula | C212H350N56O78S |
| Molecular weight | 4963.5 g/mol |
| Class | Actin-sequestering protein |
| Residues | 43 amino acids |
| Physical form | Lyophilized powder |
| Regulatory status | Not approved by the FDA for any use |
The CAS number is the reliable identifier. House codes and trade names vary between suppliers and sometimes collide outright, so when comparing material from different sources, compare the CAS number and molecular formula rather than the product name.
What the literature examines
Published work on this compound is preclinical — animal models and in-vitro systems. It is not an approved drug, and nothing below is a statement about what it does in a person.
- Binding of monomeric G-actin and the effect on actin polymerisation
- Cell migration in in-vitro scratch and transwell assays
- Angiogenesis in endothelial cell-culture models
- Expression of laminin-5 and related extracellular matrix components
We do not provide dosing, reconstitution, administration or protocol guidance for this or any compound, and we will not answer questions about using a product on a person or an animal. See our Research Use Only Policy.
Purity and verification
The practical questions for a researcher are whether the material is what it claims to be, and what fraction of the vial is that substance rather than related impurities, residual solvent or counterion salt.
Two measurements answer that. HPLC separates the sample and reports purity as a percentage of total peak area. Mass spectrometry confirms identity by measuring molecular weight against the expected 4963.5 g/mol. A certificate of analysis reports both for a specific lot.
A certificate confirms what is in the vial. It is not evidence that the material is safe or suitable for any use outside a laboratory.
Handling and storage
- Supplied lyophilized and shelf-stable at ambient temperature for shipping; no cold-chain handling is required in transit.
- For longer-term storage keep the sealed vial cold, dry and out of direct light.
- Handle in a laboratory setting with appropriate protective equipment.
- Dispose of material according to your institution's procedures and local regulations.
General stability figures are on our Storage & Handling page.
TB-500 — 10mg
Lyophilized, ≥99% purity, Certificate of Analysis available on request.