Peptide Reference
How Peptides Are Made: Synthesis Explained
Reviewed by our laboratory team · Last updated 2026-07-03
Modern research peptides are made by Solid-Phase Peptide Synthesis (SPPS), a method pioneered by Bruce Merrifield (Nobel Prize, 1984). Amino acids are added one at a time to a growing chain attached to a solid resin. After assembly the peptide is cleaved, purified by HPLC, and characterised by mass spectrometry.
Key facts
- Method
- Solid-Phase Peptide Synthesis (SPPS)
- Inventor
- Bruce Merrifield (Nobel Prize 1984)
- Purification
- Reverse-phase HPLC
- Characterisation
- Mass spectrometry (identity, purity)
Fmoc chemistry
Most modern SPPS uses Fmoc (fluorenylmethyloxycarbonyl) protecting groups. The Fmoc group is removed with base between coupling steps, allowing selective amino-acid addition.
Extended research context
The Peptide Reference deep dive
Deep dive: what 'peptide' actually means
A peptide is a short chain of amino acids linked by peptide bonds, typically 2–50 residues. Above that boundary the molecule is usually called a protein. Peptides can be endogenous (produced by the body) or synthetic (manufactured by solid-phase peptide synthesis, SPPS). The 'research peptide' category refers specifically to synthetic peptides supplied for laboratory use — not medicines, not supplements.
Why HPLC and mass spec together
HPLC (High-Performance Liquid Chromatography) reports the purity of a batch by measuring what percentage of the sample matches the target peptide's retention time. Mass spectrometry independently confirms the target's molecular weight. Together they answer two different questions: 'is it clean?' and 'is it the right molecule?'. A CoA that reports only one is incomplete.
How to read a Certificate of Analysis
A complete peptide CoA lists: batch number, HPLC purity (area %), mass-spec measured mass vs theoretical, water content (Karl Fischer), acetate/counterion content, appearance, and often endotoxin and residual solvents. Learn to spot the missing fields — that's usually where quality claims fall apart.
Research applications
- ▸Reference standards for analytical method development
- ▸Comparator peptides in receptor-binding assays
- ▸Stability testing of lyophilised material
- ▸Formulation R&D for topical and aqueous carriers
- ▸Teaching material for peptide chemistry courses
Handling checklist
- ✓Confirm HPLC ≥98% and mass-spec identity on CoA
- ✓Store lyophilised at −20 °C long-term
- ✓Reconstitute with bacteriostatic or sterile water only
- ✓Aliquot to minimise freeze/thaw cycles
- ✓Label vials with date, concentration, and batch
Common research-handling mistakes
Learnt from thousands of researcher orders across our UK labs.
✗ Buying a peptide without a CoA
Fix: Insist on an in-batch HPLC + mass-spec certificate before purchase.
✗ Using DI water for reconstitution
Fix: Use bacteriostatic (0.9% benzyl alcohol) or sterile water only.
✗ Storing lyophilised vials at room temperature long-term
Fix: Freeze at −20 °C; short-term 2–8 °C is acceptable for weeks, not months.
Continue researching
Peer-reviewed guides, comparators and matched reference materials.
Related questions researchers ask
- What is a research peptide?
- How is peptide purity measured?
- Why is HPLC the standard purity assay?
- What information is on a peptide CoA?
- Why are research peptides lyophilised?
Frequently asked questions
- Are peptides made in cells?
- Larger peptides and proteins can be made recombinantly in cells; most research peptides are chemically synthesised.
Primary sources & clinical trials
Peer-reviewed research and registered trials from PubMed, ClinicalTrials.gov, PubChem, FDA and NIH. All links open in a new tab (external, rel="nofollow").
- PubMedMerrifield SPPS reviewpubmed.ncbi.nlm.nih.gov
- StandardICH Q2(R1) · Validation of Analytical Procedures (HPLC)ich.org
- StandardUSP <1121> · Nomenclature and USP <621> Chromatographyusp.org
- PubMedFranks, Freeze-drying of pharmaceuticals — Eur J Pharm Biopharm 1998 (PMID 9884895)pubmed.ncbi.nlm.nih.gov
- PubMedManning et al., Stability of protein pharmaceuticals — Pharm Res 2010 (PMID 20143256)pubmed.ncbi.nlm.nih.gov
- FDAFDA · Peptide Drug Products — Chemistry, Manufacturing, Controls Guidancefda.gov
- EMAEMA · Guideline on development & manufacture of synthetic peptidesema.europa.eu
- PubMedNIH PubMed — Peptide purity HPLC method developmentpubmed.ncbi.nlm.nih.gov
- GuidelineGoogle — Creating helpful, reliable, people-first contentdevelopers.google.com
More Peptide Reference articles
- What Are Peptides? Complete GuidePeptides are short chains of amino acids linked by peptide bonds. Structure, size, synthesis and research uses of peptides explained.
- What Is a Peptide? Definition and ExplainedA peptide is a short polymer of amino acids linked by peptide bonds. Formal definition, boundary with proteins, and simple examples explained.
- Peptides Meaning: Terminology Explained'Peptide' comes from the Greek 'peptos', meaning digested. Common peptide terminology: oligopeptide, polypeptide, protein — clearly explained.
- What Is the Polypeptide Group?A polypeptide is a chain of many amino acids linked by peptide bonds. Definition, structural features, and relationship to proteins explained.
- Research Peptides vs Collagen PeptidesResearch peptides are defined-sequence synthetic compounds; collagen peptides are food-grade hydrolysates of collagen. Key differences explained.
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One flagship guide from every other research category — keep exploring.
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- Bacteriostatic WaterWhat Is Bacteriostatic Water?Bacteriostatic water is sterile water containing 0.9% benzyl alcohol as a bacteriostatic preservative. The benzyl alcohol inhibits bacterial growth after the vial's initial puncture, making the same vial suitable for repeated withdrawal in research handling. It is not the same as plain sterile water.