- Reference standard
- A reference standard is a characterized peptide lot whose release packet lets a laboratory defend the material's identity, purity, and handling conditions later — connecting the vial on the bench to a specific sequence, method, and lot history. It is the traceable evidence set behind a calibration, an assay control, a supplier qualification, or a published method, not a decorative certificate. Lyochem supplies reference-grade research standards at milligram-to-multi-gram scale, characterized lot by lot.
- Research-use-onlyRUO
- Research-Use-Only is a scope-of-supply label indicating that the material is a bulk research reagent for in-vitro or animal research, characterized lot by lot, and is not a finished dosage form, not labelled for human administration, and not for in-vitro diagnostic use. It is a different scope from compounding-grade or kilogram-scale API supply intended for finished-dose preparation. Buyers remain responsible for institutional biosafety review and for verifying import eligibility in the destination market.
- Retention-time identity
- Retention-time identity is the observation that a sample's main peak elutes at the same time as a qualified reference standard run under the same column, gradient, and mobile phase — a meaningful method-control signal because retention reflects hydrophobicity and net charge. It is not residue-order proof: sequence permutations, isobaric swaps, and diastereomers can co-elute within match tolerance. Lyochem treats it as appropriate for re-qualifying subsequent lots of an already-sequenced standard, with sequencing reserved for first-lot qualification.
- Monoisotopic / average mass
- Monoisotopic mass is calculated using the most abundant isotope of each element and is the value high-resolution mass spectrometry reports for smaller peptides; average mass is calculated from the average atomic weights across natural isotope abundances and is the value typically quoted for larger molecules. For example, the Lyochem catalog lists Semaglutide at an average mass of 4113.58 g/mol. A lot report states which basis applies so the observed and theoretical values are compared on the same footing.
- Impurity profiling
- Impurity profiling is the review of the minor peaks on an HPLC trace beyond the main-peak purity number — identifying deletion and truncation peptides, oxidation and deamidation products, residual protecting groups, and diastereomers, each of which points to a specific stage of the synthesis. A stable impurity fingerprint across lots is often a more informative quality signal than a single purity percentage. Lyochem can extend a lot with LC-HRMS impurity identification, assigning each impurity ≥0.5% to a class with its mass shift.
- Net peptide content
- Net peptide content is the actual peptide mass per gram of dry product, after subtracting bound water, counter-ions, and impurities — typically 70-90% of the gross weighed mass. It is determined from amino acid analysis and matters because dosing or molar calculations based on gross weight overstate the peptide actually delivered. The remainder is mostly acetate or TFA counter-ion and residual water.
- Certificate of AnalysisCOA / per-lot data packet
- A research peptide Certificate of Analysis is the batch-specific document that records identity, batch identification, and analytical results against specification — at minimum: lot number, manufacture and retest dates, appearance, RP-HPLC purity with method, ESI-MS identity, counter-ion, net peptide content, and Karl Fischer water. A full Lyochem per-lot data packet pairs the COA with the HPLC chromatogram, mass spectrum, sequence-confirmation evidence where required, and stability data, so values can be cited directly in a methods section. Endotoxin (LAL) is added for in-vivo work.
