Quality
Quality & Testing Standards
Researchers sourcing high purity peptides need documentation, not adjectives. This page explains how Resequence Peptides reports purity, which analytical methods are used and how to request the Certificate of Analysis for the exact lot you received.
Third-Party Analytical Testing
Active product lots are analyzed by independent testing laboratories rather than assessed in-house alone. Reported analytical results are supplied by the applicable laboratory and are tied to the specific lot the material was drawn from.
HPLC Purity Analysis
High-performance liquid chromatography (HPLC) is the primary method used to report peptide purity. Research materials listed on this site carry a stated purity of 98% or greater, with the exact reported figure shown on the Certificate of Analysis for that lot.
Lot-Specific Certificates of Analysis
Each documented lot is paired with its own Certificate of Analysis (COA) identifying the product, the lot number and the reported analytical results. Because results are lot-specific, always review the COA that matches the lot you received rather than a general product claim.
Identification, Packaging and Handling
Product pages state the product name, stated quantity, physical form and applicable research-use limitations. Orders are securely packaged for domestic U.S. delivery, and purchasers remain responsible for lawful storage, handling and documentation in their own laboratory setting.
Find Documentation
Certificates of Analysis are available by inquiry. Submit the product and lot information, and support will follow up with the matching documentation when available.
Purity Questions
- What does high purity mean for research peptides?
- Purity describes the proportion of the analyzed sample identified as the target peptide, most commonly measured by HPLC. A stated purity of 98% means the reporting laboratory identified 98% or more of the analyzed material as the target compound for that lot.
- How can I verify the purity of a specific lot?
- Submit a COA inquiry with the product and lot number printed on your vial. Support will provide the matching lot-specific documentation when available.
- Are analytical results the same for every lot?
- No. Analytical results are specific to the lot tested and may vary between lots. Documentation should always be reviewed per lot.
Ready to review available materials? See the research materials catalog or read our Research Use Policy.
For Research Use Only. Not for human or veterinary use. Not for human consumption. Domestic U.S. orders only. Analytical results are lot-specific and provided by third-party testing laboratories.