Terminology
Glossary
The terms you meet on certificates, product pages and in the knowledge base — briefly explained, with a pointer onward where there is more to say.
61 terms
A
- Acetylation
- Capping the N-terminus with an acetyl group, indicated by the prefix Ac-. Among other things it changes the molecule's stability. Read on →
- Age limit 21+
- Peptide Lab supplies only to buyers aged 21 or over. The declaration is requested on visiting the site. Read on →
- Agonist
- A molecule that activates a receptor. A triple-receptor agonist acts on three receptors at once. Read on →
- Aliquot
- A measured portion of a solution. Splitting into portions avoids having to thaw the whole stock every time. Read on →
- Amidation
- Converting the free carboxyl group at the C-terminus into an amide, indicated by -NH2 after the name. Read on →
- Amino acid
- The building block of a peptide. Twenty amino acids form the standard repertoire chains are built from; their order determines what a peptide is. Read on →
- Analogue
- A molecule closely resembling a naturally occurring peptide but deliberately differing at one or more points, often to change its stability.
- Antagonist
- A molecule that binds a receptor without activating it, thereby blocking an agonist's action.
B
- Bacteriostatic water
- Sterile water with 0.9% benzyl alcohol, used to reconstitute freeze-dried research peptides. A lab accessory, not a medicine. Read on →
- Batch
- One production run of a peptide. Every batch is tested separately and receives its own certificate, so a certificate never applies to the product in general.
- Benzyl alcohol
- The preservative in bacteriostatic water that inhibits the growth of micro-organisms, which is what makes repeated use of the same vial possible. Read on →
- Blend
- One vial holding two or more peptides reconstituted together. The stated quantity is the total across all components, not per component. Read on →
C
- C-terminus
- The end of a peptide carrying a free carboxyl group. In chemical synthesis this is the end anchored to the support first. Read on →
- Chromatogram
- The graph HPLC produces: time on the horizontal axis, detector signal on the vertical. Each peak is a component leaving the column at its own moment. Read on →
- COA (Certificate of Analysis)
- The analysis certificate for one tested batch: identity, purity, method and date. Not a statement about sterility or suitability for any application. Read on →
- Cold chain
- A transport and storage route that stays within a temperature range from end to end. Relevant for solutions; dry powder tolerates ambient temperature. Read on →
- Copper peptide
- A peptide with a bound copper ion, such as GHK-Cu. The metal is part of the complex, not just of the packaging. Read on →
- Coupling
- The step in which the next amino acid forms a new peptide bond with the freed N-terminus. Read on →
D
- D-amino acid
- The mirror-image form of an amino acid, as opposed to the natural L-form. Built in because peptidases shaped for the L-form get less grip on it. Read on →
- Dalton (Da)
- Unit of molecular mass. Research peptides generally fall in the range of hundreds to a few thousand daltons.
- Deletion sequence
- A chain missing exactly one amino acid because a coupling did not run to completion. It closely resembles the target molecule and therefore has to be purified out. Read on →
- Deprotection
- Removing the temporary protecting group so the N-terminus can react again. In the common Fmoc strategy this is done with a base. Read on →
- Disulfide bridge
- A bond between two sulfur-containing cysteine residues that fixes a peptide's three-dimensional shape.
F
H
- Half-life
- The time in which a concentration halves, always measured in a particular system. Buffer, plasma and a living organism give different outcomes for the same molecule. Read on →
- HPLC
- High-Performance Liquid Chromatography: a separation technique that pulls the components of a sample apart and shows what percentage is the intended peptide. It produces the purity figure on the certificate. Read on →
- Hydrolysis
- The reaction in which water splits a peptide bond. The main reason peptides are stored and shipped dry. Read on →
I
- In vitro
- Research outside a living organism, for instance in a cell culture or a test tube.
- In vivo
- Research within a living organism. Results from in vivo models do not transfer to another species as a matter of course.
- IU
- International unit: a measure based on biological activity rather than mass. Used where a weight figure does not unambiguously describe potency.
J
- Janoshik Analytical
- The independent lab that tests every Peptide Lab batch by HPLC and mass spectrometry and publishes the report on its own domain. Read on →
L
- Lot number
- The code on the vial label that points to one specific certificate. It makes the chain vial → measurement → method reconstructable after the fact. Read on →
- Lyophilisation
- Freeze-drying: freezing and letting the ice sublime directly under vacuum, leaving a dry powder without the peptide passing through a liquid phase. Read on →
- Lyophilised
- Freeze-dried. The form research peptides are supplied in: without water, hydrolysis cannot split the peptide bond. Read on →
M
- Mass spectrometry
- A measurement technique that determines a molecule's mass-to-charge ratio and thereby confirms its molecular identity. HPLC says how much is pure, MS says what it is. Read on →
- Medicine
- A product with a marketing authorisation for medical use. Research peptides do not have one and are not offered as such. Read on →
- Molecular weight
- The mass of one molecule, expressed in daltons. It sits in the specifications on the product page and is confirmed per batch by mass spectrometry. Read on →
N
- N-terminus
- The end of a peptide carrying a free amino group. By convention sequences are written from N- to C-terminus. Read on →
- Net peptide content
- How much peptide is actually in the vial, apart from counter-ions and residual moisture that weigh along. Different from purity, which only concerns the ratio between components. Read on →
O
- Oxidation
- A degradation route that sulfur-containing and aromatic amino acids are particularly sensitive to. Light can accelerate the reaction. Read on →
P
- Peak area
- The area under a peak in the chromatogram. The ratio between the target peak's area and that of all peaks together gives the purity percentage. Read on →
- Pentadecapeptide
- A chain of fifteen amino acids. BPC-157 is described this way. Read on →
- Peptidase
- An enzyme that splits peptide bonds. The reason many natural peptides are short-lived. Read on →
- Peptide bond
- The covalent bond between two amino acids, formed by condensation with the release of water. The bond that holds the chain together and that peptidases split again. Read on →
- Peptide vs. protein
- A convention, not a law of nature: chains up to roughly fifty amino acids are called peptides, longer ones polypeptides or proteins. The bond is the same in both cases. Read on →
- Preclinical
- The research phase before studies in humans, generally in cell models and laboratory animals.
- Preparative HPLC
- The same separation technique as analytical HPLC, but used to purify rather than to measure: the target peak is collected and the rest discarded. Read on →
- Protecting group
- A temporary chemical cap that stops a reactive side from joining the wrong step. Removed each cycle and cleaved off entirely at the end. Read on →
- Purity
- The share of the material that actually is the intended peptide, determined by HPLC. Peptide Lab holds a threshold of ≥99%. Read on →
R
- Receptor
- A protein structure a molecule binds to and through which it sets off a signal. Which receptor is involved largely determines a peptide's research domain.
- Reconstitution
- Dissolving freeze-dried powder in a solvent, after which the concentration follows from the amount of peptide divided by the volume added. Read on →
- Resin (support)
- The insoluble bead the growing peptide stays attached to during synthesis. It determines which end is freed later. Read on →
- Retention time
- The moment a component leaves the HPLC column. A reproducible retention time under identical conditions is an indication of identity. Read on →
- RUO (Research Use Only)
- For laboratory and research purposes only. Not for human or animal consumption, not a medicine and not medical advice. Read on →
S
- Secretagogue
- A substance that stimulates the release of an endogenous hormone rather than supplying that hormone itself. Read on →
- Sequence
- The order of amino acids in a chain. The sequence fixes a peptide's identity; the name on the label does not. Read on →
- SPPS
- Solid-phase peptide synthesis: the standard method in which the chain is built one amino acid at a time on an insoluble support, so excess reagent can simply be washed off. Read on →
T
- TFA (trifluoroacetic acid)
- The acid used to cleave the peptide from the synthesis support, often also present in the mobile phase. What remains are TFA counter-ions: they add to the weight in the vial but do not count toward the purity percentage. Read on →
- Tripeptide
- A chain of three amino acids. GHK, the basis of GHK-Cu, is one example. Read on →
V
- Vial
- The glass container the peptide is supplied in, closed with a rubber septum under an aluminium crimp.
FOR RESEARCH USE ONLY. For laboratory and research purposes only. Not for human or animal consumption; not a medicine and does not constitute medical advice.