Migration and matrix
TB-500
Also listed as TB500
Thymosin β4 fragment (acetylated heptapeptide)
- G-actin
- Formula
- C38H68N10O14
- Molar mass
- 889.01 g/mol
- CAS number
- 885340-08-9
Identity
What the molecule is, from its PubChem record. These are the figures a certificate of analysis should agree with.
- Class
- Thymosin β4 fragment (acetylated heptapeptide)
- Sequence
Ac-LKKTETQ-OH
- Seven residues, Leu-Lys-Lys-Thr-Glu-Thr-Gln: residues 17–23 of thymosin β4.
- Ac is an acetyl cap on the N-terminus.
- Molecular formula
- C38H68N10O14
- Molar mass
- 889.01 g/mol
- CAS number
- 885340-08-9
- PubChem
- CID 62707662
PubChem’s TB-500 record is the acetylated 17–23 fragment shown here. Some suppliers use the same name for full-length thymosin β4, a 43-residue protein of about 4963 g/mol (PubChem CID 45382195), so check which sequence and mass a supplier’s COA actually reports.
Checked against PubChem on 27 September 2026. Molar mass is calculated from the formula with standard atomic weights and agrees with PubChem’s published molecular weight. In sequences, H- marks a free N-terminus, -OH a free C-terminal acid and -NH₂ a C-terminal amide.
Research context
TB-500 is the acetylated 17–23 fragment of thymosin β4 (Ac-LKKTETQ), the stretch that holds the protein’s LKKTET actin-binding motif. It is studied for binding to monomeric G-actin and its influence on actin polymerisation, and in endothelial cell migration (scratch) assays that compare it with full-length thymosin β4.
Research use only. Everything on Vialwise concerns research-grade material sold for laboratory and analytical use only. It is not a registered medicine, is not supplied for human or veterinary use, and nothing here is medical advice.
Storage and handling
Store sealed lyophilised powder at −20 °C, dry and away from light.
Let the vial reach room temperature before opening, so moisture doesn’t condense on the powder.
Short and highly water-soluble, so it dissolves readily in sterile water.
Split the solution into single-use aliquots and keep them frozen, so no portion goes through repeated freeze–thaw.
General laboratory practice for this class of material; your institution’s own procedures come first. To work out concentration and aliquot volumes from a vial’s mass, use the reconstitution calculator. For the reasoning behind each step, read storing lyophilised peptides.
Published lab reports
Lab reports for TB-500 at Au Peptide Labs Our store
The one supplier whose full report list we have.
Open each lab-linked report on the lab’s own website to confirm it.
- Lab link
TB-500 5mg
Task #212994Added 31 July 2026
97.589%purity
The lab’s result row names the analyte “TB-500 (TB-4)” and gives no sequence or mass, so this report does not confirm the 17–23 fragment identity shown above.
Verify at janoshik.com
Other suppliers publish their reports on their own sites. Where each supplier publishes its COAs
Vialwise is published by APL Research Pty Ltd, which also runs Au Peptide Labs. Every supplier, ours included, is scored on the same published checklist. How we handle this
Any supplier
Check any supplier’s TB-500 COA
These checks take a few minutes and work the same on a report from any supplier, ours included. The walkthrough shows each one on a real Janoshik report.
How to verify a Janoshik COAOpen it at the lab
The report should load on the testing lab’s own website from the verify link or task number, not only as a PDF or screenshot from the supplier.
Match the name
The sample should be named TB-500 or TB500, or a clear equivalent. A different compound name means a different report.
Check which molecule
The name TB-500 is used for both the acetylated 17–23 fragment and full-length thymosin β4, so a mass-spectrometry result should state which one it found. A report that gives no sequence or mass doesn’t settle it. How HPLC and mass spec work.
Match the vial
The sample amount on the report should match the vial size you’re buying. A report on a different size or an older batch tells you less about the vial in front of you.
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