Key Takeaways
- Store lyophilized peptides at -20°C in a desiccated environment to prevent moisture absorption
- Avoid repeated freeze-thaw cycles — aliquot before freezing
- Use bacteriostatic water for multi-use vials; sterile water for single-use
- Allow vials to reach room temperature before opening to prevent condensation
- Document lot numbers and reconstitution dates for full experimental traceability
Receiving and Initial Inspection
Upon receipt, inspect packaging for damage or signs of temperature excursion. Verify the vial label matches your order (peptide name, lot number, quantity). Check that the lyophilized cake appears intact — a collapsed or discolored cake may indicate moisture exposure during shipping. If anything is suspect, photograph and contact the supplier immediately.
Documentation on Receipt
Record the lot number, received date, and storage location in your laboratory notebook or LIMS. Cross-reference with the Certificate of Analysis to confirm identity. This documentation is essential for experimental traceability and reproducibility.
Long-Term Storage Conditions
Lyophilized peptides should be stored at -20°C in a sealed container with desiccant to prevent moisture absorption. Moisture is the primary cause of peptide degradation in storage — even brief exposure to humidity can initiate hydrolysis of peptide bonds, particularly at Asp-Pro sequences.
Temperature Guidelines by Peptide Class
Most lyophilized peptides: -20°C for up to 24 months. Peptides containing cysteine or methionine: -80°C recommended to prevent oxidation. NAD+: -20°C, protect from light and humidity. Reconstituted solutions: 2–8°C for up to 7 days (peptide-dependent), or -80°C for longer storage.
Reconstitution Protocols
Before reconstituting, allow the sealed vial to equilibrate to room temperature (15–30 minutes) to prevent condensation from forming inside when opened. This condensation, if it occurs, can introduce moisture into the lyophilized powder before intentional reconstitution.
Solvent Selection
Water-soluble peptides: sterile bacteriostatic water or PBS. Hydrophobic peptides: begin with a small volume of DMSO (5–10% of final volume), then dilute with aqueous buffer. Acidic peptides (e.g., many GH-releasing peptides): 0.1% acetic acid in sterile water. Always consult the COA solubility data for your specific lot.
Reconstitution Technique
Add solvent slowly along the vial wall — do not inject directly onto the lyophilized cake. Gently swirl or roll the vial; do not vortex vigorously as this can denature peptide structure. Allow 5–10 minutes for complete dissolution. If the solution remains turbid, allow additional time before using gentle agitation. Never use sonication unless specifically recommended.
Aliquoting to Prevent Freeze-Thaw Degradation
Repeated freeze-thaw cycles are highly destructive to peptide integrity. Each cycle promotes ice crystal formation that mechanically disrupts peptide structure and promotes aggregation. Best practice is to prepare working aliquots immediately after reconstitution and store them at -80°C. Each aliquot should be thawed only once before use.
Products Relevant to This Research
These research-grade peptides are commonly used in the context described in this guide. All products are HPLC verified and include full COA documentation.
Browse All Research Peptides