Peptide research glossary
Plain-language definitions of the terms used across our catalogue — from HPLC purity to reconstitution. Written for researchers, not for marketing.
A
Agonist
A compound that binds to a receptor and activates a biological response. Research peptides such as GLP-1 receptor agonists are studied for their activity at specific receptor subtypes.
B
Bacteriostatic water
Water containing a preservative (typically benzyl alcohol) used to reconstitute lyophilised peptides to minimise microbial growth during laboratory handling.
Batch certificate
A laboratory record associated with a stated batch or submitted sample. Its report identity and scope must be checked before relating it to other products or batches.
C
Certificate of Analysis (COA)
A document issued by an analytical laboratory reporting the methods and results for a specific submitted sample. Available fields vary and should not be inferred when absent.
Cold chain
A temperature-controlled supply process (typically refrigerated) that keeps lyophilised peptides stable from production to delivery.
D
Diluent
A solvent used to dissolve a lyophilised compound before use. Common laboratory diluents for peptides are bacteriostatic water or sterile saline.
G
GHK-Cu
A copper-binding tripeptide (glycyl-L-histidyl-L-lysine) researched for its role in tissue-repair, copper transport and extracellular-matrix biology pathways.
GHRP
Growth-hormone-releasing peptide. A class of short peptides that stimulate growth-hormone release via the ghrelin receptor, studied in metabolic and GH-axis research.
GLP-1 receptor agonist
A compound that activates the glucagon-like peptide-1 receptor, researched for its effects on glucose homeostasis, appetite and energy balance in metabolic studies.
H
HPLC
High-performance liquid chromatography. An analytical technique used to measure the purity of a peptide preparation, reported as a percentage of the total sample.
I
In-vitro
Laboratory research performed outside a living organism — for example, cell cultures or receptor assays. Apex products are supplied for in-vitro research use only.
L
Lyophilisation
Freeze-drying: the removal of water from a frozen product under vacuum to produce a stable powder that can be stored and reconstituted later.
M
Melanocortin receptor
A family of G-protein-coupled receptors (MC1R–MC5R) involved in pigmentation, energy balance and endocrine signalling, studied with synthetic peptide analogues such as Melanotan II.
Molecular weight
The mass of one molecule of a compound, expressed in daltons (Da). Confirmed molecular weight is key evidence that a synthesised peptide matches its intended sequence.
N
Nasal spray
A delivery format in which a lyophilised compound is prepared for administration studies via the nasal route, often used in bioavailability research.
NAD+
Nicotinamide adenine dinucleotide. A central cellular coenzyme in metabolism, mitochondrial function and ageing biology, studied as a research compound and supplement.
P
Peptide
A short chain of amino acids linked by peptide bonds, typically under ~50 residues. Peptides are studied for their signalling and regulatory roles in biological systems.
Peptide sequence
The ordered chain of amino acids that defines a peptide's structure, written in single-letter or three-letter code, for example GHRP-6: His-D-Trp-Ala-Trp-D-Phe-Lys-NH2.
Prefilled pen
A device preloaded with a peptide solution for accurate multi-dose delivery in administration studies, often referred to as a Klik-pen format.
Purity
The proportion of the intended compound reported by a defined analytical method. A listed purity result applies to the specific sample and report, not every product or future batch.
R
Reconstitution
Dissolving a lyophilised (freeze-dried) compound in a diluent to reach the concentration required for a study protocol.
Research-use only
A supply status meaning a compound is provided exclusively for laboratory research and must not be administered to humans or animals.
S
Secretagogue
A substance that stimulates secretion — for example, a compound that triggers the release of growth hormone in endocrine research.
V
Vial
A lyophilised format supplied as powder in a sealed glass vial, to be reconstituted by the researcher before use.