Lyophilized peptides arrive as a white or off-white powder sealed under nitrogen or vacuum. The lyophilization process removes water to extend shelf life. Before use, you add solvent back. Done wrong, you degrade the compound at the first step.
What you need
- Sterile solvent: the standard diluent for most research peptides
- 1 mL graduated transfer syringe
- The peptide vial
Calculate volume before you open anything
Decide on your working concentration first. For a 5 mg vial at 1 mg/mL, you need 5 mL of solvent. Write this down. Making the calculation after you have already drawn solvent leads to dilution errors.
Let the vial reach room temperature
Cold peptide powder plus room-temperature solvent creates condensation inside the vial. Wait 15-20 minutes after removing from the refrigerator or freezer. This step gets skipped often. It should not be.
Add the solvent slowly down the glass wall
Swab the rubber stopper with alcohol. Insert the needle at a 45-degree angle, pointing toward the glass wall. Dispense the solvent slowly so it runs down the inside surface rather than hitting the powder directly. Pressure against the powder stresses peptide bonds.
Swirl, do not shake
Shaking creates foam and mechanical stress. Roll the vial between your fingers until the powder dissolves. Most peptides dissolve in 30 seconds to 2 minutes. If you see undissolved material after 5 minutes, a small amount of dilute acetic acid (0.1%) added to the solvent often helps.
HandlingStorage after reconstitution
Reconstituted peptides in sterile solvent are stable at 4°C for 4-8 weeks depending on the compound. For longer storage, aliquot before freezing at 2 to 8°C. Repeated freeze-thaw cycles accelerate degradation. Aliquot into single-use volumes at reconstitution and freeze the remainder.
When the standard solvent is not the right choice
Some longer-chain peptides and certain sequences dissolve poorly in a standard solvent alone. Dilute acetic acid (0.1-1%) is the standard alternative. Check the specific compound before assuming the standard solvent works. GHK-Cu, for example, reconstitutes readily. TB-500 often needs help.
- HPLC + MS tested, every batch
- U.S. synthesized
- Batch COA on the product page