Pioneering the future of research.
20 Aminos supplies the global scientific community with uncompromising quality and high-purity research peptides, verified, documented, and ready for the bench.
The alphabet
Expand any residue for IUPAC codes, free-form molecular formula, side chain, and a short structural note. Residue drawings will land in a later pass.
AlanineAla · A · Nonpolar
- Formula
- C₃H₇NO₂
- Side chain (R)
- –CH₃
A compact nonpolar residue with a methyl side chain. Common in peptide cores where small hydrophobic packing is preferred.
ArginineArg · R · Basic
- Formula
- C₆H₁₄N₄O₂
- Side chain (R)
- –(CH₂)₃–NH–C(NH₂)=NH
A basic residue with a guanidinium side chain that remains protonated under typical laboratory buffer conditions.
AsparagineAsn · N · Polar
- Formula
- C₄H₈N₂O₃
- Side chain (R)
- –CH₂–CONH₂
A polar amide side chain that participates in hydrogen bonding and is a common site of N-linked glycosylation motifs in proteins.
Aspartic acidAsp · D · Acidic
- Formula
- C₄H₇NO₄
- Side chain (R)
- –CH₂–COOH
An acidic residue whose carboxylate side chain is typically deprotonated near physiological pH in aqueous buffer.
CysteineCys · C · Special geometry
- Formula
- C₃H₇NO₂S
- Side chain (R)
- –CH₂–SH
A thiol-containing residue that can form disulfide bonds (cystine) and is widely used for site-specific chemistry in research peptides.
GlutamineGln · Q · Polar
- Formula
- C₅H₁₀N₂O₃
- Side chain (R)
- –(CH₂)₂–CONH₂
A polar amide homolog of asparagine with a longer side chain, frequent in solvent-exposed loops of peptide structures.
Glutamic acidGlu · E · Acidic
- Formula
- C₅H₉NO₄
- Side chain (R)
- –(CH₂)₂–COOH
An acidic residue with a carboxylate side chain one methylene longer than aspartate; common in salt-bridge networks.
GlycineGly · G · Special geometry
- Formula
- C₂H₅NO₂
- Side chain (R)
- –H
The smallest amino acid (hydrogen side chain). It confers backbone flexibility and is frequent in tight turns.
HistidineHis · H · Basic
- Formula
- C₆H₉N₃O₂
- Side chain (R)
- –CH₂–imidazole
An imidazole side chain with a pKa near neutral pH, making it useful for metal coordination and acid–base chemistry in model systems.
IsoleucineIle · I · Nonpolar
- Formula
- C₆H₁₃NO₂
- Side chain (R)
- –CH(CH₃)CH₂CH₃
A branched hydrophobic residue (β-branched). Sterically constrained backbone angles relative to leucine.
LeucineLeu · L · Nonpolar
- Formula
- C₆H₁₃NO₂
- Side chain (R)
- –CH₂CH(CH₃)₂
A branched hydrophobic residue common in amphipathic helices and hydrophobic cores of folded peptides.
LysineLys · K · Basic
- Formula
- C₆H₁₄N₂O₂
- Side chain (R)
- –(CH₂)₄–NH₂
A basic residue with a primary amine side chain, often used for conjugation and labeling chemistry in research materials.
MethionineMet · M · Nonpolar
- Formula
- C₅H₁₁NO₂S
- Side chain (R)
- –(CH₂)₂–S–CH₃
A sulfur-containing nonpolar residue; the genetic start codon encodes methionine in standard translation initiation.
PhenylalaninePhe · F · Aromatic
- Formula
- C₉H₁₁NO₂
- Side chain (R)
- –CH₂–C₆H₅
An aromatic hydrophobic residue with a benzyl side chain; contributes UV absorbance near 260 nm in peptide spectra.
ProlinePro · P · Special geometry
- Formula
- C₅H₉NO₂
- Side chain (R)
- pyrrolidine ring
A cyclic secondary amine that kinks the backbone; often breaks α-helices and defines turn geometry in peptides.
SerineSer · S · Polar
- Formula
- C₃H₇NO₃
- Side chain (R)
- –CH₂OH
A small polar residue with a hydroxymethyl side chain; a common hydrogen-bond donor/acceptor in peptide structures.
ThreonineThr · T · Polar
- Formula
- C₄H₉NO₃
- Side chain (R)
- –CH(OH)CH₃
A β-branched polar residue with a secondary alcohol; side-chain chirality adds steric constraint versus serine.
TryptophanTrp · W · Aromatic
- Formula
- C₁₁H₁₂N₂O₂
- Side chain (R)
- –CH₂–indole
The largest standard aromatic residue (indole). Strong UV absorbance near 280 nm makes it a useful spectroscopic handle.
TyrosineTyr · Y · Aromatic
- Formula
- C₉H₁₁NO₃
- Side chain (R)
- –CH₂–C₆H₄OH
An aromatic residue with a phenolic side chain; UV-active and often involved in hydrogen-bond networks at interfaces.
ValineVal · V · Nonpolar
- Formula
- C₅H₁₁NO₂
- Side chain (R)
- –CH(CH₃)₂
A β-branched hydrophobic residue that favors extended backbone conformations in peptide secondary structure.
Mission & vision
Accelerate scientific breakthroughs.
By providing researchers with the most reliable, highest-purity peptides available, backed by lot-specific documentation that survives peer review.
The trusted standard.
To be the globally trusted standard for research peptides, driving innovation in laboratory science one fully documented lot at a time.
What we stand for
What sets 20 Aminos apart.
Three commitments that guide every release in the 20 Aminos catalog.
Uncompromising quality
Every peptide is produced to 99%+ purity, your research data stays reliable and reproducible.
Strict third-party testing
Independent HPLC and ESI-MS reports accompany every batch, no exceptions, no shortcuts.
Dedicated expert support
Our scientists and support specialists guide you from order to receiving lab, and beyond.
Quality assurance
Research confidence.
From raw material sourcing to final lyophilization, 20 Aminos maintains rigorous environmental controls, temperature, humidity, particulate, so every batch meets exacting specifications.
Multi-stage testing, HPLC purity analysis, ESI-MS verification, ensures that what’s on the label is exactly what’s in the vial. Authenticity and precision, every release.
Documentation
Every batch is verified.
Comprehensive third-party testing documentation ships with every product, full chromatograms, full spectra, full chain of custody.
Chromatography
Purity documentation supporting batch-level transparency and peer review.
Mass spectrometry
Verification confirming product identity and lot-specific batch details.
Third-party docs
Every product ships with comprehensive documentation for full research review.
Certificate of analysis
Lot-specific COA, methods, raw data, validation criteria, attached to every order.
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Documentation you can check.
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Products are intended for in vitro research use only. Not for human or veterinary use. Not for diagnostic or therapeutic purposes.
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