This profile is a documentation-focused reference for TB-500 as a research material. It sets out the molecule's identity, how each lot is characterized analytically, the documentation supplied, and the storage and handling considerations a laboratory typically records. It is written for evaluating a material on paper — not as a description of any use, effect, or application, and it makes no such claims.
For current presentations and lot-specific values, see the TB-500 product page. This article provides the analytical and documentation context behind those figures.
Molecular Identity and Structure
TB-500 is a synthetic peptide whose sequence corresponds to a biologically active region of thymosin β4, a naturally occurring protein of 43 amino acids described in the scientific literature. The supplied material is a defined synthetic sequence assembled by solid-phase peptide synthesis rather than a tissue extract, which is what allows it to be reproduced consistently and compared lot to lot.
It is catalogued under CAS registry number 77591-33-4, with the molecular formula C212H350N56O78S and a reported mass of approximately 4963 Da. At that mass it is the largest peptide in the catalog, a fact that informs how it is handled at the bench.
Specifications at a Glance
The following reference values describe the material as characterized. Lot-specific figures are always those printed on the accompanying Certificate of Analysis, which takes precedence over any general reference.
| Attribute | Reference value |
|---|---|
| CAS number | 77591-33-4 |
| Molecular formula | C212H350N56O78S |
| Reported mass | ~4963 Da |
| Parent protein | Region of thymosin β4 (43-aa protein) |
| Physical form | White lyophilized powder |
| Identity method | LC-MS |
| Purity method | RP-HPLC (area %) |
| Storage | -20 °C, protected from light |
| Classification | Research use only |
Analytical Characterization
Two complementary, orthogonal methods characterize each lot.
Purity — reverse-phase HPLC
Reverse-phase HPLC resolves the target peptide from synthesis-related impurities and reports purity as an area-percent value for the tested sample under the stated method. The figure is interpretable only alongside the conditions that produced it.
Identity — LC-MS
LC-MS confirms the material by measuring its molecular mass and comparing it to the theoretical mass of the sequence — a particularly useful check for a large peptide, where mass accuracy distinguishes the intended product from truncated or modified sequences. The distinction between purity and identity is explained in how identity and purity are verified.
Documentation and Lot Traceability
Each lot is supplied with documentation that ties the physical material to its analytical record: a Certificate of Analysis recording purity, mass confirmation, and release date (see the guide to Certificates of Analysis); the supporting RP-HPLC purity report; and an independent third-party analytical report from a separate laboratory. The unique lot identifier connects all three to the container and the order record.
Storage and Handling Considerations
TB-500 is stored as a lyophilized powder at -20 °C, protected from light. Because it is the highest-molecular-weight peptide in the catalog, dissolution on reconstitution can take slightly longer than for shorter sequences; allowing the solvent to stand and swirling gently rather than shaking helps bring the full quantity into solution and limits foaming. As with other peptides, reconstituted material is commonly divided into single-use aliquots and kept cold to minimize freeze–thaw cycling. Solvent, concentration, and handling are determined by the researcher against the protocol. General principles are covered in research material storage practices.
Research Context
TB-500 appears in the laboratory research literature as a synthetic peptide of interest. This profile intentionally does not describe, summarize, or imply any biological activity, effect, outcome, or application. Any research use is defined and bounded by the investigating laboratory's protocols, institutional SOPs, and applicable safety and regulatory requirements.
What This Profile Does and Does Not Establish
This is a documentation reference. It does not, on its own, establish any of the following:
- That the material is appropriate for a specific research workflow — suitability is a laboratory determination made against institutional SOPs.
- That every unit in a shipment is identical to a tested sample; analysis is performed on a sample, not on each container.
- Any biological effect, activity, or outcome — none is claimed or implied.
- Fitness for human or veterinary use, diagnosis, treatment, or consumption. TB-500 is supplied for laboratory research use only.
Key Takeaways
- TB-500 is a synthetic peptide based on a region of thymosin β4 (CAS 77591-33-4; ~4963 Da), supplied as a lyophilized powder for research use only.
- Identity is confirmed by LC-MS; purity is reported by RP-HPLC — two distinct, complementary methods.
- As the largest peptide in the catalog, it dissolves best with unhurried, gentle reconstitution.
- Each lot carries a COA, an RP-HPLC purity report, and an independent third-party report tied by a lot identifier.
