Technical library
This page defines the terms that appear on a peptide quote.
Definitions for the terms that appear on a quotation and a batch certificate. 22 terms.
| Analogue | A molecule deliberately altered from a reference sequence. An analogue is a different substance from the compound it derives from, and it carries its own identifiers. |
| Batch | The unit of production a certificate belongs to. Documentation should reference the batch rather than the order, because orders get split and consolidated while batches do not. Reading a certificate |
| Blend | A presentation containing more than one named compound, mixed at fill. A blend cannot be characterised by a single molecular formula, so its certificate has to account for each component. Recovery compounds |
| CAS number | A unique registry identifier for a chemical substance. It is the least ambiguous way to confirm two suppliers are quoting the same material, since trade names vary and abbreviations collide. See the compound range |
| Certificate of Analysis | The batch-specific document recording what was measured, by what method, on what date, and by whom. Six fields make it useful, and the absence of any one makes it decorative. Reading a certificate |
| Contract filler | A business that holds the end-customer relationship and fills or finishes product under its own arrangements. A buyer type, not a supplier type. How private label works |
| GMP | Good Manufacturing Practice. Production conditions covering process, equipment and environment. It describes the site, not the molecule, and it belongs to whoever operates that site. How batches are documented |
| HPLC | High-performance liquid chromatography. The method used to separate the components of a sample and quantify the main peak. It answers a purity question, not an identity question. How batches are documented |
| International unit | A unit defined by an agreed reference preparation rather than by mass. Fills quoted in international units cannot be compared directly with fills quoted in milligrams, which is a common way to misread a quote. HGH specification |
| ISO 9001:2015 | A quality management system standard covering consistency, risk management and continuous improvement. Like GMP it certifies an organisation, not a product. How batches are documented |
| Lyophilised | Freeze-dried to a solid. Removing the water is what gives the dry form its shelf life, which is why a reconstituted vial has a materially shorter one. Storage and stability |
| Marketing authorisation | The permission a medicine needs before it can be placed on a market. Several compounds in this range hold one in the EU, several hold none, and which applies is a national question. Requirements by market |
| Minimum order quantity | The smallest quantity a supplier will produce or release. Whether it is set per compound or per order changes the figure entirely, so the basis matters as much as the number. Wholesale supply terms |
| Molecular formula | The count of each atom in a molecule. Useful for confirming identity between quotes, and meaningless for a preparation that is a mixture rather than a single defined substance. See the compound range |
| Private label | Supply carrying the buyer's brand on the vial and the carton, with documentation issued under the buyer's product name where required. How private label works |
| Reconstitution | Adding a solvent to a lyophilised powder. Concentration is determined entirely by how much solvent is added, so two identical vials can present as very different concentrations. Concentration calculator |
| Retest date | The date by which a batch should be reanalysed rather than assumed. Distinct from an expiry date, and only meaningful alongside a record of how the material was stored. Storage and stability |
| Reverse charge | The VAT mechanism for intra-EU business supply, under which the buyer accounts for the VAT rather than the supplier charging it. It requires a validated VAT number. Wholesale supply terms |
| Sequence | The order of amino acids in a peptide, written in single-letter code. It is the most specific identity check available short of running the analysis yourself. See the compound range |
| Specification | What a batch is required to achieve. Distinct from a result, which is what a named batch actually achieved when measured. A certificate quoting only a specification describes an intention. Reading a certificate |
| Supplementary protection certificate | An instrument extending exclusivity beyond a patent's expiry, granted per country. It is why a compound patent expiring does not necessarily open a market. Requirements in the Netherlands |
| Wholesale distribution authorisation | The licence a business needs to import and distribute medicines in a given market. The name and the issuing body differ by country. Requirements by market |
The two that cause the most trouble
Specification against result, and international units against milligrams
A specification is what a batch was required to achieve. A result is what it achieved when measured. A certificate quoting only the first describes an intention, and it is the commonest way a document looks reassuring while establishing nothing.
International units are defined by an agreed reference preparation rather than by mass, so a fill quoted in them cannot be compared with one quoted in milligrams. Three compounds in our range are filled that way. A quote that looks cheaper per vial may simply be a different unit.
Ask about a term
If a term on a quotation is unclear, ask and we will clarify it.
| Working through a supplier decision? Tell us the compounds and the market. | Talk to us |
Also in the library
Related reference material
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Work out the concentration of a reconstituted vial, how much compound sits in a given draw volume, and how many draws a vial yields.
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How to read a Certificate of Analysis
What a batch certificate must contain, what each section actually tells you, and the six ways a weak certificate gives itself away.
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Storage and stability
Lyophilised and reconstituted storage conditions, what degrades a peptide, and how to specify storage in a supply agreement.
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