Full-length thymosin β4, a 43-amino-acid synthetic peptide, N-terminally acetylated. It is used in in vitro work on peptides of the β-thymosin family and their analytical characterisation. 10 mg vial, lyophilized powder, ≥99% HPLC purity verified by third-party analysis. For research use only.
Research areas
- Peptides of the β-thymosin family
- Full-length protein vs short fragment comparison
- Analytical characterisation (HPLC, mass spectrometry)
Technical data
| Field | Value |
|---|---|
| Name | TB-500 (thymosin β4) |
| Amount per vial | 10 mg |
| Composition | Full-length thymosin β4, 43 amino acids, N-terminally acetylated |
| Molecular weight | ≈ 4,963 Da |
| Form | Lyophilized powder (unless stated otherwise) |
| Purity | ≥ 99% (HPLC) — see batch COA |
| Ships from | France, within 24 business hours |
TB-500: short fragment or full-length thymosin β4? Mass settles it
This is the most common confusion on this reference. The name "TB-500" originally referred to a short 7-residue peptide reproducing the LKKTET motif (residues 17 to 22 of thymosin β4). In practice, much of what circulates under that label is the full 43-amino-acid protein. They are different molecules, and the price of one vial does not compare with the other.
Two criteria settle it, both readable on the certificate of analysis:
| Full-length thymosin β4 | Short fragment | |
| Chain length | 43 amino acids | 7 amino acids |
| Expected mass | ≈ 4,963 Da | ≈ 900 Da |
A vial labelled "fragment" with a mass around 5,000 Da actually describes the full protein — and vice versa. This reference is full-length thymosin β4: the mass measured on the COA should fall around 4,963 Da.
Why choose NEXUS TB-500
- Third-party verified purity: every batch is analysed by HPLC by an independent laboratory, and the certificate of analysis (COA), which reports the measured mass, can be viewed before ordering.
- Checkable identity: the expected mass (≈ 4,963 Da) is on the COA — verification happens before the vial is even opened.
- Shipped from France: parcel prepared within 24 business hours, delivered in 2 to 5 business days in France and 8 European countries. Free shipping from €120.
- Consistent quality: same supplier, same controls, same packaging from batch to batch.
- Verified reviews: customers leave their feedback on Trustpilot; we do not edit it.
Reconstitution and handling
The lyophilizate is reconstituted with bacteriostatic water, which contains benzyl alcohol and therefore keeps the solution preserved after opening.
Add the solvent slowly down the vial wall, let it run, then swirl gently: no vigorous shaking, no vortex — shear denatures peptides. The solvent volume never changes the mass in the vial, only the resulting concentration. Our reconstitution calculator gives the concentration for any volume.
Storage
Lyophilized powder: -20 °C or below, protected from light and moisture; stable for years when unopened. After reconstitution: 2–8 °C, protected from light, with a reference shelf life of 28 days. For longer storage, frozen aliquots are preferable to repeated freeze-thaw cycles.
Common laboratory mistakes
- Comparing two "TB-500" vials without checking the mass. A fragment (≈ 900 Da) and the full protein (≈ 4,963 Da) are not the same molecule.
- Using plain sterile water for a vial that will be opened several times. Without a preservative, the solution is no longer protected once the stopper has been pierced more than once.
- Vortexing the vial or repeatedly refreezing the solution. Shear denatures the peptide and each freeze-thaw cycle degrades a fraction. Aliquot at reconstitution.
- Reconstituting a 10 mg vial like a 5 mg one. At equal solvent volume, the concentration doubles.
Frequently asked questions
TB-500 and thymosin β4: is it the same product?
The name TB-500 is used both for full-length thymosin β4 and for a short fragment. This reference is full-length thymosin β4, 43 amino acids, as its mass of about 4,963 Da confirms.
How can it be told apart from the short fragment sold under the same name?
By mass: about 4,963 Da for the full protein, about 900 Da for the 7-residue fragment. The value is stated on the certificate of analysis.
What should be checked on the certificate of analysis?
HPLC purity of at least 99%, and the measured mass, expected around 4,963 Da. The COA for every batch can be viewed from the Quality page and on request before ordering.
What should this peptide be reconstituted with?
Bacteriostatic water, which contains benzyl alcohol and keeps the solution preserved after opening. Plain sterile water is unsuitable once the vial is pierced more than once.
How long does the reconstituted solution keep?
28 days at 2–8 °C, protected from light. Beyond that, frozen aliquots are preferable to repeated freeze-thaw cycles.
Where is the order shipped from and how fast?
From France, within 24 business hours. Delivery to a pickup point or to the door, in 2 to 5 business days depending on the country. Free from €120.
In what context may this product be used?
Exclusively for laboratory and in vitro research, by qualified personnel. It is not intended for human or animal consumption, nor for diagnostic or therapeutic use.
NEXUS Quality Standard
Every NEXUS research compound is produced under strict quality control procedures. Each batch undergoes independent analytical testing to verify identity, assay accuracy, purity, microbial safety, endotoxin levels, heavy metal screening, and full batch traceability.
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For laboratory research only. TB-500 10mg is not suitable for human or animal consumption. Not a drug, food or cosmetic. To be handled by qualified personnel in accordance with applicable regulations.