47 terms
Peptide Research Glossary
Every lab term you'll bump into — from HPLC to reconstitution — explained in plain English, with links to the compounds they relate to.
- Acetate Salt Molecular Basics
- A common counter-ion form in which synthetic peptides are supplied (e.g. GHRP-2 acetate). The salt form affects net peptide content by weight.
- GHRP-2 Acetate →Gonadorelin Acetate →Net Peptide Content
- Aliquot Handling & Storage
- A measured portion split off from a larger sample so the remainder is not repeatedly handled or thawed.
- Freeze–Thaw Cycle
- Amino Acid Molecular Basics
- The building block of peptides and proteins. Twenty standard amino acids link together in a specific order to form every peptide sequence.
- Peptide BondAmino Acid Sequence
- Amino Acid Sequence Molecular Basics
- The exact order of amino acids in a peptide, written from the N-terminus to the C-terminus. The sequence defines a peptide's identity.
- Amino AcidN-Terminus / C-Terminus
- Bacteriostatic Water Handling & Storage
- Sterile water containing 0.9% benzyl alcohol, which inhibits bacterial growth so a multi-use vial can be accessed repeatedly in the lab.
- Bacteriostatic Water →ReconstitutionSterile Water
- Batch / Lot Number Testing & Analysis
- An identifier linking a vial to one production run, so its documentation can be traced and matched.
- Certificate of Analysis (COA)
- C-Terminal Amidation Molecular Basics
- Replacing the C-terminal carboxyl group with an amide. It is a common modification that can increase resistance to enzymatic breakdown in research models.
- N-Terminus / C-Terminus
- Certificate of Analysis (COA) Testing & Analysis
- A document reporting test results for a specific batch, such as identity, purity and method. A COA applies only to the lot number it lists.
- Batch / Lot NumberHPLC
- Collagen
- The main structural protein of connective tissue and skin; its synthesis is a common endpoint in skin-model research.
- GHK-Cu →
- Concentration Handling & Storage
- The amount of compound per unit volume, e.g. mg/mL. It equals compound mass divided by diluent volume and is separate from vial size or package count.
- Reconstitution
- Copper Peptide (GHK-Cu)
- A naturally occurring tripeptide bound to copper, studied in skin and extracellular-matrix research models.
- GHK-Cu →Collagen
- Cyclic Peptide Molecular Basics
- A peptide whose chain forms a ring. Cyclization can make a peptide more rigid and more resistant to enzymes than its linear form.
- Peptide
- Dalton (Da) Molecular Basics
- A unit of molecular mass equal to 1 g/mol. Large molecules are often expressed in kilodaltons (kDa).
- Molecular Weight
- Endotoxin Testing & Analysis
- Bacterial cell-wall material (lipopolysaccharide) that can interfere with cell-based research. It is measured with separate tests such as LAL, not by HPLC.
- SterilityPurity
- Freeze–Thaw Cycle Handling & Storage
- Repeatedly freezing and thawing a solution. Multiple cycles can degrade peptides, so labs often divide solutions into aliquots.
- Aliquot
- GHRH Analog
- A compound modeled on growth-hormone-releasing hormone, studied for its action on pituitary GHRH receptors.
- CJC-1295 (no DAC) →Sermorelin →Tesamorelin →Growth Hormone Secretagogue
- GIP
- Glucose-dependent insulinotropic polypeptide, a second incretin hormone. Tirzepatide is researched as a dual GIP/GLP-1 receptor agonist.
- Tirzepatide →Retatrutide →GLP-1
- GLP-1
- Glucagon-like peptide-1, an incretin hormone studied in metabolic research. Compounds such as semaglutide are studied as GLP-1 receptor agonists.
- Semaglutide →Tirzepatide →Retatrutide →GIPReceptor Agonist
- Growth Hormone Secretagogue
- A compound that stimulates growth-hormone release, often through the ghrelin (GHS-R1a) receptor in research models.
- Ipamorelin →GHRP-2 Acetate →GHRP-6 Acetate →GHRH Analog
- Half-Life
- The time for a compound's concentration to fall by half in a given system. Reported values depend heavily on the model and conditions studied.
- C-Terminal Amidation
- HPLC Testing & Analysis
- High-Performance Liquid Chromatography separates a sample's components so the main peak can be compared with impurities. It is the usual method for reporting purity percentage.
- PurityMass Spectrometry (MS)Certificate of Analysis (COA)
- Hygroscopic Handling & Storage
- Readily absorbs moisture from air. Many lyophilized peptides are hygroscopic, so vials should warm to room temperature before opening.
- Lyophilization
- In Vitro / In Vivo
- In vitro studies happen in cells or test tubes; in vivo studies happen in living organisms. Findings in one don't automatically transfer to the other.
- Research Use Only (RUO)
- International Unit (IU) Handling & Storage
- A measure of biological activity, not mass. IU values (as on HCG) cannot be converted to milligrams without compound-specific data.
- HCG →Concentration
- LC-MS Testing & Analysis
- Liquid chromatography coupled with mass spectrometry, combining separation and identity confirmation in one analysis.
- HPLCMass Spectrometry (MS)
- Lyophilization Handling & Storage
- Freeze-drying: water is removed from a frozen sample under vacuum, leaving a stable dry powder or 'cake'. Most research peptides ship lyophilized.
- ReconstitutionStorage Temperature
- Mass Spectrometry (MS) Testing & Analysis
- Measures the mass-to-charge ratio of molecules to confirm a compound's identity against its expected molecular weight. It confirms what is in the vial, not how pure it is.
- HPLCMolecular Weight
- Mitochondria
- Organelles that produce most of a cell's ATP. Mitochondrial function is a major topic in cellular aging research.
- SS-31 →MOTS-c →NAD+ →NAD+
- Molecular Weight Molecular Basics
- The mass of one mole of a molecule, expressed in g/mol or daltons (Da). It is used to confirm identity by mass spectrometry and in molar calculations.
- Mass Spectrometry (MS)
- N-Terminus / C-Terminus Molecular Basics
- The two ends of a peptide chain: the N-terminus carries a free amino group and the C-terminus a free carboxyl group. Modifications at either end can change stability.
- Amino Acid SequenceC-Terminal Amidation
- NAD+
- Nicotinamide adenine dinucleotide, a coenzyme involved in cellular energy metabolism and studied in aging biology.
- NAD+ →Mitochondria
- Net Peptide Content Testing & Analysis
- The actual peptide mass as a share of total powder weight, after accounting for water and counter-ions. It is different from HPLC purity.
- PurityAcetate Salt
- Peptide Molecular Basics
- A short chain of amino acids joined by peptide bonds, typically 2 to about 50 residues. Longer chains are usually called proteins.
- Peptide BondPolypeptide
- Peptide Blend Molecular Basics
- A single vial containing two or more compounds at stated quantities, e.g. 5mg + 5mg. Each component's amount should be listed separately.
- BPC-157 + TB-500 Blend →CJC-1295 (no DAC) + Ipamorelin →
- Peptide Bond Molecular Basics
- The covalent amide bond formed between the carboxyl group of one amino acid and the amino group of the next, releasing a water molecule.
- Amino Acid
- Polypeptide Molecular Basics
- A longer, unbranched chain of amino acids. Polypeptides fold into three-dimensional structures and may form proteins.
- Peptide
- Purity Testing & Analysis
- The share of the target compound relative to detected impurities, usually by HPLC peak area. Purity alone does not establish sterility, endotoxin levels or safety.
- HPLCNet Peptide ContentSterility
- Receptor Agonist
- A molecule that binds a receptor and activates it, mimicking a natural signaling molecule.
- GLP-1Receptor Antagonist
- Receptor Antagonist
- A molecule that binds a receptor without activating it, blocking the natural signal.
- Receptor Agonist
- Reconstitution Handling & Storage
- Dissolving a lyophilized powder in a liquid diluent so it can be used in laboratory work. The chosen volume sets the solution's concentration.
- Bacteriostatic Water →Bacteriostatic WaterConcentration
- Research Use Only (RUO) Testing & Analysis
- A labeling designation for materials intended for laboratory research, not for human or veterinary use, diagnosis or treatment.
- In Vitro / In Vivo
- Solid-Phase Peptide Synthesis (SPPS) Molecular Basics
- The standard method for 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 and purified.
- HPLCLyophilization
- Sterile Water Handling & Storage
- Water free of living microorganisms but with no preservative. Once opened it is generally intended for single use.
- Bacteriostatic Water
- Sterility Testing & Analysis
- The absence of viable microorganisms, confirmed only by dedicated sterility testing. It is a separate property from purity.
- EndotoxinPurity
- Storage Temperature Handling & Storage
- Lyophilized peptides are commonly kept cold (refrigerated or frozen) and away from light; reconstituted solutions are usually refrigerated and used within a limited window. Follow the product's supplied guidance.
- LyophilizationFreeze–Thaw Cycle
- Telomere
- Repetitive DNA at chromosome ends that shortens with cell division; studied as a marker in cellular aging research.
- Epithalon →
- Third-Party Testing Testing & Analysis
- Analysis performed by an independent laboratory rather than the seller or manufacturer. The report should name the lab, method and batch.
- Certificate of Analysis (COA)
Educational definitions for laboratory research context only — not medical or dosing advice. More questions? See the FAQ or our research guides.