TB-500 (Thymosin Beta-4) — Research Compound Overview

Section 01

What Is TB-500?

TB-500 is a synthetic peptide derived from Thymosin Beta-4 (Tβ4) — a naturally occurring 44-amino acid protein first isolated from the bovine thymus gland. TB-500 corresponds specifically to the active region of Thymosin Beta-4: the 43-amino acid fragment designated Ac-LKKTETQ that encodes the protein's actin-binding and actin-sequestering domain.

Thymosin Beta-4 was identified in the 1960s and 1970s as part of the thymosin fraction of thymic peptides. Subsequent research identified the Ac-LKKTETQ sequence as the biologically active segment responsible for most of the protein's studied activities in actin dynamics and cell mobility. TB-500 is the synthetic analog of this fragment and is the form most commonly used in peer-reviewed research.

• Chemical identity: Ac-LKKTETQ — a 43-amino acid synthetic peptide; active fragment of the 44-amino acid Thymosin Beta-4 protein
• Class: Synthetic peptide derived from Thymosin Beta-4 (Tβ4); actin-sequestering protein
• Origin: Thymosin Beta-4 first discovered in thymus gland tissue; TB-500 is the synthetic analog of the active fragment
• Molecular weight: Approximately 4,964 Da (43 amino acids, acetylated N-terminus)
• Physical form: Lyophilized (freeze-dried) white powder — requires reconstitution prior to use in research protocols
• Classification: Research compound — for licensed professionals and qualified researchers only

The amino acid sequence Ac-LKKTETQ represents the actin-binding domain of Thymosin Beta-4, identified in studies on G-actin (globular actin) sequestration. This domain is associated with actin dynamics regulation, which forms the basis for much of the cell migration and connective tissue biology research involving this peptide.

Section 02

Research Background

Thymosin Beta-4 and its active fragment TB-500 have been the subject of substantial peer-reviewed research across multiple disciplines. The research literature on Thymosin Beta-4 spans several decades, with published investigations covering actin biology, cell migration mechanisms, angiogenesis pathways, and connective tissue dynamics.

Key research areas documented in the peer-reviewed literature include:

Section 03

TB-500 in Research Context

TB-500 has been employed across a variety of research disciplines. The following reflects applications as reported in published peer-reviewed literature — not as clinical claims or indications for human use.

• Actin biology: TB-500 binds G-actin (globular actin) via its Ac-LKKTETQ sequence, and published research has examined its role in regulating the G-actin to F-actin (filamentous) ratio within cells — a key mechanism in cytoskeletal dynamics
• Cell migration models: Research has investigated TB-500's influence on epithelial and endothelial cell migration in scratch assay and transwell migration models — a methodology commonly used in tissue repair biology research
• Cardiac tissue research: Published studies have examined Thymosin Beta-4 in cardiac progenitor cell activation contexts and post-ischemic tissue models in animal studies
• Neuronal studies: Peer-reviewed research has investigated TB-500 in neuronal survival models and central nervous system injury research settings
• Corneal and ocular research: Published investigations have examined TB-500 in corneal epithelial wound models in preclinical settings

• Storage (lyophilized): Typically stored at −20°C, protected from light and moisture, for long-term stability
• Storage (reconstituted): 2–8°C; use within the timeframe specified in applicable research protocols
• Reconstitution solvent: Bacteriostatic water is the standard solvent for multi-use research protocols

Section 04

Sequence Labs TB-500 Supply

Sequence Labs supplies TB-500 as a research compound for licensed professionals and qualified researchers. All products are independently tested and carry batch-specific Certificates of Analysis.

Section 05

Reconstitution Reference

The following is provided as a general reference for researchers working with lyophilized peptide compounds. Researchers should follow their own institutional protocols and consult applicable regulatory guidelines. This is not medical or clinical instruction.

1. Verify compound identity and COA. Confirm the batch COA from Krause Analytical prior to use. Verify via Finnrick Pulse if needed. Confirm that storage conditions (−20°C, protected from light) have been maintained throughout transit and storage.
2. Prepare bacteriostatic water. Bacteriostatic water (0.9% benzyl alcohol preserved) is the standard reconstitution solvent for multi-use research protocols. Use sterile technique throughout the preparation process.
3. Introduce solvent slowly to the vial. Direct the bacteriostatic water gently down the interior wall of the vial to minimize foaming. Do not introduce solvent directly onto the lyophilized cake. Allow the research preparation to dissolve without mechanical agitation — do not shake.
4. Roll to mix. Gently roll the vial between your palms to aid complete dissolution. TB-500, as a 43-amino acid peptide, may require gentle rolling for several minutes to achieve full reconstitution.
5. Inspect the research sample. The reconstituted solution should appear clear. Discard if particulate matter or unusual color is observed and consult COA documentation.
6. Label the vial. Record compound name, concentration (mg/mL), reconstitution date, and researcher/protocol identifier per institutional requirements.
7. Store at 2–8°C. Refrigerate the reconstituted research preparation. Do not freeze reconstituted vials. Use within the timeframe established in your research protocol documentation.

Section 06

Frequently Asked Questions

Common questions from licensed researchers and practitioners regarding TB-500 research documentation, supply, and purity standards.