What is TESTAGEN?
TESTAGEN is a synthetic tetrapeptide belonging to the Khavinson class of short-peptide bioregulators. Its primary structure is H-Lys-Glu-Asp-Gly-OH, commonly abbreviated by the single-letter code KEDG, comprising four L-amino acid residues joined by standard peptide (amide) bonds. The sequence combines a basic residue (lysine) with two acidic residues (glutamic and aspartic acid) and a C-terminal glycine, giving the molecule a compact, highly polar, zwitterionic character typical of this bioregulator family.
Structurally, TESTAGEN is closely related to other members of the short-peptide bioregulator series, differing from its analogues by the identity of a single terminal residue. This class of di-, tri-, and tetrapeptides was originally described through the analysis of tissue-peptide fractions, and members are catalogued by their exact residue composition rather than by any assigned physiological role. Within a research context, TESTAGEN is treated as a defined-sequence reference standard for investigating this compact peptide scaffold.
In the neutral scientific literature, Khavinson-class short peptides such as TESTAGEN are studied in vitro as model compounds for sequence-specific peptide-nucleic acid interaction research and comparative structure-activity studies of short-peptide bioregulators. American Peptides supplies TESTAGEN strictly as a research chemical for these laboratory investigations. It is not a drug, dietary supplement, or therapeutic agent, and it is not intended for human or veterinary use, diagnostic procedures, or any form of administration.
Reconstitution & handling
TESTAGEN is provided as a lyophilized (freeze-dried) powder and should be brought to room temperature in its sealed vial before opening to minimize condensation onto the hygroscopic solid. As a short, highly polar tetrapeptide bearing ionizable lysine, glutamate, and aspartate side chains, KEDG is generally readily soluble in aqueous solvents; sterile water or bacteriostatic water is the conventional reconstitution medium for laboratory stock solutions. The diluent should be introduced slowly, directed against the vial wall rather than injected forcefully onto the powder, then allowed to dissolve with gentle swirling. Vortexing, sonication, or aggressive agitation is avoided to limit foaming and mechanical shear on the peptide.
If any residual material resists dissolution, brief warming to room temperature and continued gentle mixing are preferred over harsh mechanical action; for peptides with limited initial wetting, a small volume of dilute acetic acid can serve as a pre-solubilizing agent before dilution to the final aqueous working concentration, a standard chemistry technique for polar peptides. All handling should be performed under clean conditions to preserve the integrity of the reconstituted material, and prepared solutions should be clear and free of visible particulates.
Storage & stability
In its lyophilized form, TESTAGEN is best stored sealed and protected from light, moisture, and heat; short-term holding at refrigerated temperatures and long-term storage frozen (for example, at or below -20 degrees C) help preserve the dry peptide over extended periods. Because the powder is hygroscopic, exposure to ambient humidity should be minimized and desiccated conditions are preferred. Once reconstituted, the peptide is less stable than the dry solid and should be kept refrigerated, protected from light, and used within a short working window; aliquoting the stock solution into single-use portions before freezing avoids repeated freeze-thaw cycles, which can degrade short peptides through hydrolysis and aggregation.
How it's tested
Each lot of TESTAGEN is characterized to a specification of ≥99% purity by reversed-phase high-performance liquid chromatography (RP-HPLC), which resolves the target tetrapeptide from process-related impurities and quantifies chromatographic purity. Identity is confirmed by mass spectrometry (MS), where the measured monoisotopic/average mass is compared against the theoretical mass calculated from the H-Lys-Glu-Asp-Gly-OH sequence to verify the correct molecular species. A Certificate of Analysis (COA) documenting these results is available for the material, providing lot-specific purity and identity data so that researchers can confirm the reference standard before use.