research peptides FAQ

Don't. Once reconstituted with bacteriostatic water, peptides degrade through oxidation, aggregation, and microbial contamination even under refrigeration. Lyophilized peptides stored at −20°C remain stable for 12–24 months, but reconstituted solutions lose potency after 28 days regardless of storage conditions. Prepare only the volume needed for immediate experiments and keep the remaining powder frozen.

Request the batch-specific HPLC chromatogram and mass spectrometry report before using the compound. If the supplier cannot provide these within 48 hours, the peptide should be considered unverified. Proceeding with experiments introduces an uncontrolled variable that invalidates reproducibility. Reputable peptide suppliers maintain digital archives of every batch report and can retrieve them on demand.

Contact the supplier immediately and request a replacement batch or refund. A peptide below 98% purity contains sufficient impurities to compromise experimental reproducibility, and using it means any resulting data will be unreliable. Reputable suppliers replace out-of-spec batches at no cost. Resistance to replacement is a red flag signaling the purity issue isn't isolated to one batch.

Request MS data before using the peptide. HPLC verifies purity but not sequence accuracy. A peptide can show 98% purity on HPLC while containing the wrong amino acid sequence. Mass spectrometry is the only method that confirms molecular weight matches the expected structure. Suppliers who refuse to provide MS data are either not testing it or hiding failed results.

Do not use the peptide if the package arrived warm to the touch or if ice packs were completely liquefied. Temperature excursions above 8°C for extended periods (more than 6 hours) cause protein denaturation that HPLC analysis at your facility may not detect because the peptide's primary structure (amino acid sequence) remains intact while the tertiary structure (functional shape) is compromised. Contact the supplier for a replacement shipment with temperature data logger verification.