TB-500 — Research Peptide (10mg Vial)

TB-500 is a research peptide related to thymosin beta-4 (Tβ4), a 43-residue, N-terminally acetylated protein known in biochemistry for binding monomeric actin. M-Rogue Research supplies TB-500 as a lyophilized powder in a 10mg vial, shipped from our California warehouse.

The name TB-500 is not used consistently across the research-peptide market. It most commonly refers to a short synthetic fragment of Tβ4, Ac-Leu-Lys-Lys-Thr-Glu-Thr-Gln (residues 17–23, the actin-binding motif), but some suppliers use it for the full-length 43-residue sequence. The ILS Laboratories COA for our lot reports the identity as “TB-4”. Because these two materials differ substantially in mass and formula, the specifications below list both until the exact form of this lot is confirmed. In the laboratory, Tβ4 and its fragments are used in cell-free actin-binding assays, in vitro cell-culture studies and analytical method development.

Chemical Specifications

Note: Form supplied in lot 2026-01: to be confirmed with the supplier. The COA lists identity as “TB-4” by HPLC retention time, which does not by itself establish which form is present.

Third-Party Testing & Verification

The current lot of TB-500 10mg (lot 2026-01) was analyzed by ILS Laboratories in San Diego, California. The certificate lists M Rogue Research as the client (“Tested for: M Rogue Research”).

Certificate COA-2026-S5VB1M (analysis date 08/25/2026) reports an HPLC peptide purity of 99.85% against a specification of ≥95.0%, a net peptide content of 10.62 mg, identity confirmed by HPLC retention-time comparison with a reference standard, and a fentanyl immunoassay screen (50 ng/mL cutoff) reported as not detected. Purity is calculated by reversed-phase HPLC area normalization at 214 nm, as the percentage of the target peptide relative to all peptide-related peaks. The COA lists the identity analyte as “TB-4”.

This COA covers lot 2026-01 only. It reports HPLC data and does not include mass-spectrometry data. View the TB-500 10mg COA

Storage & Reconstitution Guidelines

TB-500 10mg is supplied as a lyophilized (freeze-dried) powder in a sealed vial. In this form the peptide is considerably more stable than in solution, but it is still sensitive to moisture, heat and light. On receipt, store the unopened vial at -20°C, protected from light, in a dry container. Short periods at room temperature during transit are normal for lyophilized material.

Before opening, allow the vial to reach room temperature (typically 15–30 minutes) so that atmospheric moisture does not condense on the cold powder. Reconstitute with a solvent appropriate to your assay, such as sterile water or a suitable buffer; some sequences dissolve more readily in a small volume of dilute acetic acid or DMSO before dilution. Add solvent slowly down the vial wall and swirl gently rather than shaking or vortexing.

Once in solution, divide the material into single-use aliquots to avoid repeated freeze-thaw cycles. Store aliquots at -20°C (or -80°C for longer periods) and keep solutions in use at 2–8°C for short periods only. Record the lot number, solvent, concentration and date on every aliquot. For a full walkthrough, see our guide on lyophilized peptide handling, reconstitution and storage.

Compliance Disclaimer

All compounds are intended strictly for laboratory and scientific research purposes only. Not for human or animal consumption. For research purposes only. Not for human consumption. 21+.

Documentation & Further Reading

• Certificates of Analysis page
• How to Read and Verify a Peptide COA
• LC-MS vs HPLC: How Molecular Identity is Confirmed
• Overview of Common Research Peptides in In Vitro Science
• Frequently asked questions