Quality Standards

Our Minimum Standard

Every compound we carry is held to a minimum purity threshold of 99% as confirmed by independent HPLC analysis. This standard applies to every production lot, not just initial batches. Lots that test below 99% purity are not released for sale.

Why Documentation Matters

In the research peptide market, purity claims are easy to make. Verification is harder. Without documentation, there is no way for a researcher to confirm that what they received matches what was advertised.

Documentation matters for three reasons:

• Research integrity. Experiments depend on consistent, correctly-identified compounds. An impure or mislabeled compound can invalidate results without any obvious indication of the problem.
• Batch-to-batch consistency. Lot-specific documentation allows researchers to track compound quality across orders and identify if a batch performs differently from prior ones.
• Supplier accountability. A supplier willing to publish verifiable documentation from independent laboratories is accountable in a way that a supplier making undocumented claims is not.

When evaluating any research peptide supplier, ask for the COA for the specific lot you are purchasing — not a generic or sample document. Ask which laboratory performed the testing and whether results are from the manufacturer or an independent facility.

HPLC Analysis

High-Performance Liquid Chromatography (HPLC) is the primary method used to determine compound purity. The process separates chemical components of a sample by passing them through a column under high pressure. Each component elutes at a different time, producing peaks on a chromatogram.

The area under each peak is proportional to the quantity of that component. Purity is calculated as the percentage of the area attributable to the target compound versus all detected components. A compound reporting 99.2% purity by HPLC means 99.2% of the detected signal corresponds to the target molecule.

HPLC does not identify what impurities are present — only that they are present below the purity threshold. Mass spectrometry is used for identity confirmation.

Mass Spectrometry Identity Confirmation

Mass spectrometry measures the mass-to-charge ratio of ionized molecules in a sample. For peptides, this confirms molecular identity by matching the observed mass to the theoretical mass of the target compound.

This is a critical step that HPLC alone cannot provide. A compound could show high HPLC purity but be an incorrect sequence, an analogue, or a degradation product with similar chromatographic behavior. MS analysis confirms that the dominant compound in the sample is molecularly consistent with the stated identity.

Lot-Specific Certificates of Analysis

A Certificate of Analysis (COA) is a document that records the test results for a specific production lot of a compound. A valid, lot-specific COA includes:

• Compound name and CAS number where applicable
• Production lot number (matching the label on the vial)
• Test date
• Test methods used (HPLC, MS, or both)
• Purity percentage result
• Appearance description
• Pass/Fail release determination
• Name of testing laboratory

The lot number on your COA should match the lot number printed on your product vial. If these do not match, the documentation does not apply to what you received.

Storage Standards

Lyophilized (freeze-dried) peptides are chemically stable but sensitive to improper storage conditions. OPSEK Labs stores all compounds at -20°C in controlled-environment facilities from the point of receipt through fulfillment.

Shipments include ice packs and insulated thermal packaging designed to maintain product temperature during standard domestic transit times. We do not ship compounds without cold-chain packaging regardless of ambient temperature or order size.

After receipt, compounds should be stored at -20°C in their original sealed vials until needed. See our Storage & Handling Guide for compound-specific guidance.

How to Evaluate Any Peptide Supplier

When assessing a research peptide supplier, consider the following:

• Does the supplier provide lot-specific COAs, or generic sample documents?
• Is testing performed by an independent laboratory, or reported by the manufacturer only?
• Does the COA include HPLC data, MS confirmation, or both?
• Does the lot number on the COA match the vial you received?
• Are compound specifications (molecular weight, sequence, appearance, storage) published on each product page?
• Can you contact the supplier with documentation questions and receive a substantive response?

OPSEK Labs meets all of these criteria. Suppliers that cannot or will not provide this level of documentation should be treated with appropriate caution in a research context.