Semax 10mg

A synthetic short peptide of 7 amino acids ending in the Pro-Gly-Pro motif. It is used in in-vitro work on proline-rich short peptides, their stability in solution and their analytical characterisation. 10 mg vial, lyophilized powder, ≥99% HPLC purity verified by third-party analysis. For laboratory research use only.

Research areas

• Synthetic short peptides
• Solution stability of proline-rich sequences
• Analytical characterisation (HPLC, mass spectrometry)

Technical data

Semax or N-acetyl Semax amidate: mass settles it

Two compounds circulate under almost identical names. The Semax offered here is the unmodified heptapeptide. The so-called N-acetyl Semax amidate carries an acetyl group at the N-terminus and an amide at the C-terminus. On a product page the difference is two words; on the certificate of analysis it shows at once:

A gap of about 41 Da in the measured mass points to the other form. The trap most people fall into: the two forms do not share the same molar mass, so 10 mg of one does not hold the same number of molecules as 10 mg of the other — about 12.3 µmol for Semax versus 11.7 µmol for the acetylated amidated form. Comparing series run with one and then the other without correcting for this skews the comparison by about 5%.

Worked example: reconstituting a 10 mg vial

With 2 ml of bacteriostatic water added to the 10 mg vial:

• resulting concentration: 10 mg ÷ 2 ml = 5 mg/ml, i.e. 5,000 µg/ml;
• as a molar concentration: 5 g/l ÷ 813.9 g/mol ≈ 6.1 mmol/l;
• split into 0.5 ml aliquots, the solution gives 4 fractions of 2.5 mg, to be frozen separately.

The solvent volume never changes the mass of peptide in the vial: 1 ml gives 10 mg/ml, 4 ml gives 2.5 mg/ml. The total stays 10 mg; only the dilution changes. Our reconstitution calculator runs this calculation for any volume.

Why choose this NEXUS product

• Third-party verified purity: every batch is HPLC-tested by an independent laboratory, and the certificate of analysis (COA) can be consulted before ordering.
• Shipped from France: parcels prepared within 24 business hours, delivered in 2 to 5 business days in France and 8 European countries. Free shipping from €120.
• Consistent quality: same supplier, same controls, same packaging from one batch to the next.
• Verified reviews: our customers leave their feedback on Trustpilot; we do not edit it.

Reconstitution and handling

The lyophilisate is reconstituted with bacteriostatic water, which preserves the solution once the vial has been opened; the 3 ml vial covers the full reconstitution of this 10 mg vial. Add the solvent slowly down the vial wall, let it run, then swirl gently: no vigorous shaking and no vortexing, as shear denatures peptides.

Storage

The lyophilized powder keeps at -20 °C or below, protected from light and moisture; unopened and stored this way, the lyophilisate is stable for several years. After reconstitution, store at 2–8 °C, protected from light, with a reference shelf life of 28 days. For longer storage, freezing aliquots is preferable to repeated freeze–thaw cycles.

Common laboratory mistakes

• Confusing Semax with N-acetyl Semax amidate. The names look alike, the masses do not: 813.9 Da versus about 855.0 Da.
• Comparing masses instead of amounts of substance. At equal mass the two forms do not contain the same number of molecules (about 5% apart).
• Using plain sterile water for a vial that will be opened several times. Without a preservative the solution is unprotected once the stopper has been pierced several times.
• Vortexing the vial. Gentle swirling is enough, even if dissolution takes a minute.
• Repeatedly refreezing the reconstituted solution. Each cycle degrades a fraction of the peptide. Aliquot right after reconstitution.