Cresten Labs sells only through crestenlabs.eu and orders@crestenlabs.eu. Any other site or social account using our name is not us.
Research Use Only, not for human or veterinary consumption Ships across the EU single market Verified, every batch →
Order status
Buy Peptides
Research Areas Verification About Contact Methodology Editorial Calculator Bulk RFQ
Glossary, pharmacological terms

35 working terms,
defined.

Reference definitions for the analytical, chemical, and pharmacological terminology used across Cresten editorial, methodology, and product pages. Use Cmd+F or Ctrl+F to find a specific term.

Acetate (salt form)
A counter-ion form of a peptide. Acetate-form peptides are the default for Cresten Labs catalog. Compared with TFA (trifluoroacetic acid) salt form, acetate has lower toxicity in cell culture and is preferred for biological assays. Salt form does not change the peptide sequence.
Agonist
A compound that binds a receptor and activates it, mimicking the action of an endogenous ligand. Contrasts with antagonist (binds and blocks) and partial agonist (binds and partially activates).
Allosteric modulator
A compound that binds a receptor at a site other than the orthosteric (primary ligand-binding) site, modulating the receptor’s response to its endogenous ligand. Positive allosteric modulators (PAMs) enhance, negative (NAMs) reduce.
Antagonist
A compound that binds a receptor without activating it, blocking endogenous ligands from binding. Competitive antagonists can be displaced by higher ligand concentration; non-competitive antagonists cannot.
Bacteriostatic water
Sterile water containing 0.9% benzyl alcohol as a preservative. Standard reconstitution diluent for lyophilized peptides at the bench. Multi-dose vials allow repeated reconstitution from a single vial. Not for protocols requiring true sterile (preservative-free) water.
Bioburden
Total microbial contamination present in a sample, measured as colony-forming units (CFU). Tested on every Cresten batch via plate count methods (TAMC for total aerobic microbial count, TYMC for total yeast and mould count) per Ph. Eur. specification.
CAS number
Chemical Abstracts Service Registry Number. A unique identifier assigned to every chemical compound by the American Chemical Society. Used for institutional procurement, regulatory documents, and database lookups. BPC-157’s CAS number is 137525-51-0.
CLND (Chemiluminescent Nitrogen Detector)
A detector method used to quantify the actual peptide content in a vial by measuring nitrogen-containing compounds. Gives a peptide content percentage that is more rigorous than HPLC purity alone, because HPLC measures peptide-relative purity but does not measure how much of the vial mass is actually peptide.
Certificate of Analysis (COA)
A formal laboratory document detailing the analytical results for a specific batch of compound: identity, purity, content, contamination panels, and analyst signature. Cresten publishes the COA before stock is released.
Counter-ion
The ion paired with a charged peptide during purification. Most peptides ship as TFA salts by default; Cresten ships as acetate salt. Counter-ion content is reported on the COA and contributes to gross-vs-net weight calculations.
Endotoxin
Lipopolysaccharide (LPS) from gram-negative bacteria, a contaminant that triggers inflammation in cell culture and animal models. Cresten tests every batch via the Limulus Amebocyte Lysate (LAL) assay per Ph. Eur. specification. Acceptable limits expressed in EU/mg.
FTIR (Fourier-transform infrared spectroscopy)
An identity confirmation method that measures how a compound absorbs infrared light, producing a characteristic spectrum. Useful for confirming structural features and detecting impurities not visible by HPLC.
Gross weight
The total mass of material in the vial, including the peptide, water of hydration, counter-ion (acetate or TFA), and any residual solvents. Industry standard for quantifying lyophilized peptides. Net peptide content is reported separately on the COA.
HPLC (High-Performance Liquid Chromatography)
The standard method for quantifying peptide purity. Compounds are separated by their interaction with a stationary phase under high-pressure flow; the area under the main peak relative to total peak area gives the purity percentage. Cresten reports HPLC purity to two decimal places on every COA.
Hill notation
The IUPAC convention for writing molecular formulas. Carbon first, hydrogen second, then other elements alphabetically. BPC-157 in Hill notation is C₆₂H₉₈N₁₆O₂₂.
IC50
The concentration of a compound at which it produces 50% of its maximum inhibitory effect. Used to compare potency across compounds in receptor-binding and enzyme-inhibition assays. Lower IC50 means higher potency.
InChI Key
A 27-character chemical identifier derived from the IUPAC International Chemical Identifier (InChI). Hash-based, structure-derived, unique to each compound. Used for cheminformatics database lookups and cross-referencing.
Janoshik Analytical
The accredited analytical laboratory in Czech Republic that verifies every Cresten batch. Third-party laboratory specializing in peptide analytical chemistry. Each Cresten COA is signed by Janoshik analysts.
Kd (dissociation constant)
The concentration at which a ligand occupies 50% of receptor binding sites at equilibrium. Lower Kd means higher binding affinity. Reported in molar units (M, mM, µM, nM).
LAL assay
Limulus Amebocyte Lysate. The standard endotoxin detection method, using a clotting reaction from horseshoe crab blood cells. Sensitivity in the picogram-per-millilitre range. Required by Ph. Eur. for any compound destined for parenteral research.
LC-MS (Liquid Chromatography Mass Spectrometry)
A combined separation and identification technique. Compounds are separated by HPLC, then ionized and analyzed by mass spectrometer. Gives both peak area (purity) and exact mass (identity confirmation). Standard for confirming peptide identity on a COA.
Lyophilization (freeze-drying)
The process of removing water from a peptide by sublimation under vacuum. Produces a freeze-dried cake or powder that is stable at room temperature for weeks to months. Cresten ships all peptides lyophilized.
Mannitol
A sugar alcohol used as a bulking agent in some lyophilized peptide products. Cresten does not use mannitol. The vial contains exactly the labelled mass of pure peptide, nothing else.
Net peptide content
The actual mass of peptide in a vial, expressed as a percentage of total vial mass. Distinct from HPLC purity (which measures peptide-relative purity within the peptide fraction). Cresten quantifies net peptide content via CLND on every batch.
Ph. Eur. (European Pharmacopoeia)
The official compendium of quality standards for pharmaceutical substances in the European Union. Cresten methodology references Ph. Eur. specifications for endotoxin, bioburden, and other analytical parameters where applicable.
PubChem CID
PubChem Compound Identification number, assigned by the National Center for Biotechnology Information (NCBI) at the US National Library of Medicine. Used for chemical database lookups and cross-referencing. BPC-157’s PubChem CID is 9941957.
Purity (HPLC)
The percentage of total HPLC peak area attributable to the main peak (the target compound). Cresten specification is ≥99.0% for catalog peptides; current a live batch certificate publishes here once the first batch is listed.
Pyroglutamyl (pGlu)
A spontaneous cyclization that can occur when N-terminal glutamine (Gln) or glutamic acid (Glu) is present in a peptide sequence. The resulting pGlu peptide is included in HPLC purity reporting. Considered a normal subset of such peptides, not an impurity in the regulatory sense.
Reconstitution
The process of dissolving a lyophilized peptide in a diluent (typically bacteriostatic water or sterile water) to produce a working solution. Volume and diluent depend on target concentration and downstream use.
SMILES (Simplified Molecular Input Line Entry System)
A line-notation chemical structure standard, computer-readable. Enables cheminformatics software to reconstruct the full 2D and 3D structure of any compound from a single text string.
Salt form
The counter-ion paired with the peptide. Cresten ships acetate salt by default. Alternate salt forms (TFA, chloride, ammonium) available on quote.
Sequence (one-letter, three-letter)
The amino acid composition of a peptide written in standard codes. One-letter: G, E, P, P, P, G, K, P, A, D, D, A, G, L, V (BPC-157). Three-letter: Gly-Glu-Pro-Pro-Pro-Gly-Lys-Pro-Ala-Asp-Asp-Ala-Gly-Leu-Val. Both encode the same sequence.
Stability (freeze-dried, reconstituted)
How long a peptide retains its specification. Lyophilized peptides are stable for weeks to months at 2 to 8°C; reconstituted solutions are typically stable for 4 to 6 weeks at 2 to 8°C, less if subjected to repeated freeze-thaw cycles.
Sterile water for injection
Preservative-free water meeting Ph. Eur. specification. Used for protocols incompatible with benzyl alcohol (the preservative in bacteriostatic water).
TFA (trifluoroacetic acid)
A common counter-ion in peptide synthesis, used during HPLC purification. Most catalog peptides ship as TFA salt by default. TFA can interfere with some biological assays; Cresten ships as acetate by default to avoid this.