This library provides scientific and educational context on research-use-only materials — how they are documented, tested, and stored. Nothing here constitutes usage, dosing, or administration guidance, and all materials are intended solely for laboratory and scientific research.
Certificates of Analysis
A Certificate of Analysis (COA) is the primary quality document that accompanies a research compound. It reports the results of the analytical testing performed on a specific production lot, letting a researcher confirm a material’s identity, purity, and physical characteristics before use.
What a COA Confirms
A COA documents the measured properties of a specific lot — not a general marketing claim. It ties analytical results to a lot or batch number so the material in hand can be traced directly to the tests performed on it.
Identity
Confirmation that the compound is what it claims to be, typically established by mass spectrometry matching the expected molecular weight of the target sequence.
Purity
The proportion of the target compound relative to impurities, usually reported as a percentage from HPLC analysis (for example, ≥99%). Higher purity reduces the chance that impurities confound experimental results.
Physical Description
The appearance and form of the material (for example, a white lyophilized powder) and, where applicable, moisture/water content and net peptide content.
How to Read One
Match the compound name and lot number on the COA to the material you received, check the reported purity against the stated specification, and note the analytical methods and test date. A COA with no lot number, no methods, or no measured values offers little assurance.
Viewing Sample COAs
Sample COAs are available directly from the catalog — open a compound’s detail panel and select “View COA (PDF).” Comparing a real document against the points above is the fastest way to become comfortable reading them.
Purity & Identity Testing
Two analytical techniques underpin most peptide quality documentation: high-performance liquid chromatography (HPLC), which measures purity, and mass spectrometry (MS), which confirms identity. Together they answer the two core questions about any compound — is it the right molecule, and how pure is it?
High-Performance Liquid Chromatography (HPLC)
HPLC separates the components of a sample as they travel through a column at different rates. Each component appears as a peak, and the area of the target peak relative to the total is reported as purity (area %). It is the standard method for quantifying how much of a sample is the intended compound versus impurities.
Mass Spectrometry (MS)
Mass spectrometry measures the mass-to-charge ratio of ionized molecules to produce a precise molecular weight. Comparing the measured mass to the calculated mass of the target sequence confirms identity — that you have the molecule you expect, not a mislabeled or incorrect one.
Why It Matters
Impurities and misidentified compounds are a leading source of irreproducible research. A documented purity figure and a confirmed mass let a researcher treat material quality as a controlled variable, rather than discovering it after an experiment fails to replicate.
Reading the Numbers
Purity is typically expressed as a percentage (for example, 98–99%+). Molecular weight is expressed in daltons (Da) and should match the theoretical weight of the stated sequence within the instrument’s tolerance.
Lyophilization & Storage
Most research peptides are supplied as lyophilized (freeze-dried) powders. Lyophilization removes water under vacuum, leaving a dry, stable solid that withstands shipping and long-term storage far better than a solution would. Proper storage and handling preserve that stability.
What Lyophilization Is
Lyophilization, or freeze-drying, freezes the material and then removes the ice directly as vapor under vacuum (sublimation). The result is a dry powder or cake with very low moisture, which slows the chemical and physical degradation peptides undergo in solution.
Storage Conditions
Lyophilized material is generally most stable when kept cold, dry, and protected from light. Long-term storage is commonly at −20 °C or colder in a sealed container with desiccant; shorter-term storage is often acceptable at refrigerated temperatures. Always follow the storage guidance on the product documentation.
Handling the Powder
Allow a cold, sealed vial to reach room temperature before opening. This prevents atmospheric moisture from condensing onto the cold contents, which would introduce water into an otherwise dry material. Minimize exposure to air and humidity while handling.
Why Form Matters
The dry, lyophilized state is what gives research peptides their shelf stability. Keeping the material dry and cold until it is needed is the single most important factor in preserving the quality documented on its COA.
Nomenclature & Identifiers
Research peptides are described by a consistent set of identifiers — their amino acid sequence, molecular weight, and registry numbers. Understanding this shorthand lets researchers verify that a product matches the compound they intend to study.
Amino Acid Sequence
A peptide is a chain of amino acids, and its sequence is the ordered list of those residues. Sequences are written using either three-letter codes (e.g., Gly-Pro-Glu) or single-letter codes (e.g., GPE), read from the N-terminus to the C-terminus. The sequence uniquely defines the peptide.
Molecular Weight
The molecular weight (or molecular mass), expressed in daltons (Da), is the combined mass of the constituent amino acids minus the water lost as they bond. It is the value confirmed by mass spectrometry and serves as a primary identity check.
CAS Registry Numbers
A CAS Registry Number is a unique numerical identifier assigned to a specific chemical substance by the Chemical Abstracts Service. When available, it provides an unambiguous reference to a compound across literature and suppliers, independent of naming variation.
Naming Variation
Many compounds are known by several names — a systematic name, a common name, a code, or a nickname. Sequence, molecular weight, and CAS number are the reliable identifiers when names differ; always verify a compound by these rather than by name alone.
Glossary of Terms
Common terms used throughout research-compound documentation.
Certificate of Analysis (COA)
A document reporting the analytical test results for a specific production lot, confirming identity, purity, and physical characteristics.
HPLC
High-Performance Liquid Chromatography; the standard analytical method for measuring the purity of a compound.
Mass Spectrometry (MS)
An analytical method that measures molecular mass to confirm a compound’s identity.
Lyophilized
Freeze-dried; processed into a dry, stable powder by removing water under vacuum.
Purity
The proportion of a sample that is the target compound, typically reported as a percentage from HPLC.
Molecular Weight (Da)
The mass of a molecule expressed in daltons; the sum of its constituent atomic masses.
Peptide
A short chain of amino acids linked by peptide bonds.
Amino Acid
The building-block molecules that link together to form peptides and proteins.
Sequence
The ordered list of amino acids that defines a specific peptide, read from the N-terminus to the C-terminus.
CAS Number
A unique identifier assigned to a chemical substance by the Chemical Abstracts Service.
Endotoxin
A bacterial contaminant measured to assess the cleanliness of a preparation; lower levels indicate a cleaner material.
Lot / Batch Number
An identifier tying a specific production run to its analytical testing and documentation.
GMP
Good Manufacturing Practice; a system of quality standards governing how materials are produced and controlled.
Research Use Only (RUO)
A designation indicating a product is intended solely for laboratory and scientific research, not for human or veterinary use.
Looking for a specific compound’s documentation? Browse the catalog to view per-compound COAs, or contact our research team with questions.