Research peptide glossary
Definitions of the terms used across our product pages, certificates and guides, from amino acid sequence to stock solution.
A
- Aliquot
- A measured portion of a stock solution, divided out so the remaining stock is not exposed to repeated freeze–thaw cycles or contamination.
- Amino acid sequence
- The order of amino-acid residues in a peptide, written from the N-terminus to the C-terminus using three-letter (Gly-Glu-Pro) or one-letter (GEP) codes.
B
- Bacteriostatic water
- Sterile water containing 0.9% benzyl alcohol, which inhibits bacterial growth. It is used as a diluent when a reconstituted stock will be sampled more than once. Read more
- Batch (lot) number
- An identifier for material produced and tested together. It links a vial to the laboratory documentation for that batch.
- Bioregulator peptide
- A very short peptide, typically two to four amino acids long, studied mainly in Russian gerontology research for proposed gene-regulatory activity. Examples are Epithalon and Pinealon. Read more
C
- CAS number
- A unique numeric identifier that the Chemical Abstracts Service assigns to a chemical substance. It identifies a compound unambiguously across suppliers and literature.
- Certificate of analysis (CoA)
- A laboratory report for one batch, stating identity and purity results, the methods used, the testing laboratory and the test date. Read more
- Counter-ion
- An ion, such as acetate or trifluoroacetate (TFA), that is bound to a peptide as a salt during synthesis and purification. Counter-ions count towards powder mass but not towards peptide content.
F
- Freeze–thaw cycle
- One round of freezing and thawing a solution. Repeated cycles can degrade peptides, which is why stocks are divided into single-use aliquots.
G
- Growth hormone secretagogue (GHS)
- A compound studied for stimulating growth hormone release from pituitary somatotrophs, through either the GHRH receptor (e.g. CJC-1295) or the ghrelin receptor GHS-R1a (e.g. Ipamorelin). Read more
H
- HPLC (High-performance liquid chromatography)
- An analytical method that separates the components of a sample. Peptide purity is reported as the target peak’s share of total UV-absorbing peak area. Read more
I
- In vitro
- Experiments done with cells, tissues or biochemical systems outside a living organism, for example in culture plates or test tubes.
L
- Lyophilisation (Freeze-drying)
- Removing water from a frozen solution by sublimation under vacuum. It leaves a dry powder that is more stable in storage than a solution.
M
- Mass spectrometry (MS, LC-MS)
- An analytical method that measures mass-to-charge ratio. It confirms a peptide’s identity by matching its observed molecular mass to the expected mass.
- Molecular weight
- The mass of one mole of a compound, in g/mol (daltons). It is used to convert between mass and molar concentration.
N
- Net peptide content
- The share of a lyophilised powder’s mass that is peptide, as opposed to counter-ions and residual water. It is distinct from HPLC purity.
P
- Peptide
- A chain of amino acids joined by peptide (amide) bonds, typically 2 to about 50 residues long. Longer chains are generally called proteins. Read more
- Preclinical research
- Research carried out before any human study, including in-vitro experiments and animal models.
- Purity
- For peptides, the HPLC peak area of the target compound as a percentage of all UV-absorbing components detected in the sample.
R
- Reconstitution
- Dissolving a lyophilised powder in a diluent to make a solution of known concentration. 1 mg/mL equals 1 µg/µL. Read more
- Research peptide
- A synthetic peptide supplied for in-vitro and preclinical laboratory research, not as a licensed medicine. Read more
- Research use only (RUO)
- Labelling that means a product is intended solely for laboratory research. It is not for diagnostic or therapeutic use and not for human or veterinary use. Read more
S
- Solid-phase peptide synthesis (SPPS)
- The standard method of making synthetic peptides. Amino acids are added one at a time to a chain anchored on a resin bead, then the finished peptide is cleaved off and purified.
- Stock solution
- A concentrated solution of known strength, prepared once and diluted or aliquoted for experiments.
Research use only. For in-vitro laboratory research use only. Not for human or veterinary use.
More answers: FAQ · research guides · concentration calculator.