Research Glossary
Peptide research terms, defined.
A working glossary of the terms you will encounter on this site and across peptide-research literature. Concise, research-context, no medical framing.
Glossary
Agonist
A molecule that binds to a receptor and activates a biological response. Peptide agonists mimic endogenous ligands at their target.
Glossary
Aliquot
A measured sub-volume of a stock solution, separated for individual use to limit freeze-thaw cycles on the master sample.
Glossary
Analogue
A compound structurally similar to a reference molecule with targeted modifications — often to extend half-life, increase receptor selectivity or shift pharmacokinetics.
Glossary
Antibody
A protein produced by the immune system that specifically binds a target antigen. Used in ELISA and related assays for detection of peptide binding events.
Glossary
Assay
A controlled laboratory procedure that measures a specific property — binding affinity, enzyme activity, cellular response — of a compound.
Glossary
BAC water
Bacteriostatic water: sterile water containing 0.9% benzyl alcohol used as a diluent to prevent microbial growth during short-term storage of reconstituted peptides.
Glossary
Binding affinity
The strength with which a ligand attaches to its receptor. Typically expressed as a dissociation constant (Kd); lower Kd means tighter binding.
Glossary
Cold chain
An unbroken chain of controlled-temperature storage and transport. Critical for peptides that degrade at ambient temperatures.
Glossary
COA
Certificate of Analysis. The document that lists purity, identity and related quality data for a specific batch of a compound.
Glossary
Dose-response
A curve relating a compound’s concentration to the magnitude of its measured effect. Fundamental to characterising potency in vitro.
Glossary
ELISA
Enzyme-Linked Immunosorbent Assay. A plate-based assay used to detect and quantify peptides, antibodies and other proteins.
Glossary
GHRH
Growth Hormone Releasing Hormone — an endogenous peptide that stimulates growth hormone release. Target class for several research analogues.
Glossary
GHRP
Growth Hormone Releasing Peptide — a class of synthetic compounds that stimulate growth hormone release via the ghrelin receptor.
Glossary
GLP-1
Glucagon-Like Peptide-1 — an incretin hormone involved in glucose homeostasis. Target of heavily studied metabolic research peptides.
Glossary
Half-life
The time required for the concentration of a compound to fall to half its original value. Short half-lives require more frequent dosing in research protocols.
Glossary
HPLC
High-Performance Liquid Chromatography. The analytical method used to quantify purity of peptide preparations.
Glossary
In vitro
Performed outside a living organism — typically in test tubes, plates or cell culture.
Glossary
In vivo
Performed within a living organism in a controlled research setting.
Glossary
Ligand
Any molecule that binds a receptor. Peptides are endogenous ligands for many membrane receptors.
Glossary
Lyophilized
Freeze-dried powder form. Peptides are commonly supplied lyophilized for stability; water is added at the point of research use.
Glossary
Mass spec
Mass Spectrometry. Confirms the molecular mass of a compound, verifying peptide identity and detecting impurities.
Glossary
Molarity
A concentration unit expressing moles of solute per litre of solution. Standard for describing peptide stock concentrations in research.
Glossary
Peptide
A short chain of amino acids — typically 2 to 50 residues — linked by peptide bonds. Longer chains are classified as proteins.
Glossary
Purity
The percentage of the active compound in a sample, relative to impurities and degradation products. Expressed as a number on the COA.
Glossary
Receptor
A protein that a peptide or other ligand binds to, triggering a downstream biological response.
Glossary
Reconstitution
The process of adding diluent to a lyophilized peptide to produce a solution for research use.
Glossary
Research use only
The explicit positioning of a compound as a laboratory research tool, not intended for human use, therapy or consumer application.
Glossary
Vial
The sealed glass container in which lyophilized peptides are supplied. Rubber-stoppered to allow sterile diluent addition.
Research Use
Definitions, not prescriptions.
Every definition above refers to terminology used in laboratory research. Nothing on this page constitutes medical, therapeutic or human-use guidance. See the full Research-Use Disclaimer.