What is THYMOSIN ALPHA-1?
Thymosin Alpha-1 is a synthetic single-chain polypeptide belonging to the thymosin family of small, acidic, thymus-associated peptides. It is catalogued under CAS number 62304-98-7 and corresponds to the molecular formula C129H215N33O55 with an average molecular weight of 3108.30 g/mol. As supplied, the material is a chemically defined, non-glycosylated peptide prepared by solid-phase synthesis and characterized to reference-standard specifications.
Structurally, the peptide comprises 28 amino acid residues in the defined sequence Ac-Ser-Asp-Ala-Ala-Val-Asp-Thr-Ser-Ser-Glu-Ile-Thr-Thr-Lys-Asp-Leu-Lys-Glu-Lys-Lys-Glu-Val-Val-Glu-Glu-Ala-Glu-Asn, in which the N-terminal serine residue carries an acetyl (Ac-) modification. The sequence is notably acidic, rich in aspartate and glutamate residues, which contributes to a low isoelectric point and strong aqueous solubility. The absence of cysteine residues means the molecule does not form intramolecular disulfide bonds, and its backbone is characteristically extended and largely unstructured in aqueous solution rather than adopting a rigidly folded conformation.
Thymosin Alpha-1 is used as a reference peptide in in-vitro and preclinical laboratory investigation, where it is studied in the context of immunological signaling research and cellular assay development. In this catalog it is offered strictly as a research chemical for laboratory experimentation, analytical method development, and comparative structure-activity studies. It is not a drug, dietary supplement, or article intended for human or veterinary use, and no physiological or clinical outcome is claimed or implied.
Reconstitution & handling
Thymosin Alpha-1 is provided as a lyophilized (freeze-dried) solid and requires reconstitution in a suitable aqueous solvent prior to use in laboratory work. Because of its highly acidic residue composition, the peptide is readily soluble in water and in aqueous buffers; sterile or bacteriostatic water is commonly selected as the reconstitution solvent for this class of material. To dissolve, the diluent should be introduced slowly against the wall of the vial and the solution allowed to stand until the solid is fully in solution, with gentle swirling rather than vigorous vortexing to minimize mechanical shear and foaming.
When preparing a working stock, the peptide should be brought to room temperature before opening to limit condensation onto the hygroscopic solid, and the reconstituted material handled aseptically. Solutions are best evaluated for complete dissolution before use, as any visible turbidity may indicate incomplete solvation or the presence of particulates. This monograph addresses only the chemistry of dissolution and handling.
Storage & stability
In its lyophilized form, Thymosin Alpha-1 is most stable when stored sealed and protected from moisture and light at low temperature, typically at or below -20°C, where the dry peptide retains integrity over extended periods. Once reconstituted, the peptide is less stable and should be kept refrigerated at 2-8°C for short-term use or aliquoted and frozen at -20°C or below for longer storage; repeated freeze-thaw cycling should be avoided, as it can promote aggregation and degradation. Aliquoting into single-use fractions at the time of reconstitution is the recommended practice to preserve purity across the working lifetime of the material.
How it's tested
Each lot of Thymosin Alpha-1 is analytically characterized to confirm identity and purity before release. Purity is determined by reversed-phase high-performance liquid chromatography (RP-HPLC), with material specified at ≥99% by HPLC. Molecular identity is confirmed by mass spectrometry (MS), which verifies the intact molecular weight of 3108.30 g/mol against the theoretical value derived from the C129H215N33O55 formula and 28-residue sequence. A Certificate of Analysis (COA) documenting the chromatographic purity profile and mass-spectrometric confirmation is available for the material, providing lot-specific verification of the analytical specifications.