What Are Peptides?
Peptides are short chains of amino acids linked by peptide bonds, typically fewer than about fifty residues. In research settings they are usually produced synthetically, characterised by analytical methods such as HPLC and mass spectrometry, and supplied as lyophilized reference material for in-vitro laboratory work.
Published 2026-08-22 · Updated 2026-08-22 · Reviewed by the Lana editorial team
What defines a peptide?
A peptide is a sequence of amino acids joined by amide (peptide) bonds. The distinction between a peptide and a protein is conventional rather than absolute: chains up to roughly fifty residues are generally described as peptides, while longer folded chains are described as proteins.
How are research peptides produced?
Most research peptides are produced by solid-phase peptide synthesis, in which the sequence is assembled one residue at a time on a resin support, then cleaved, purified by preparative chromatography, and lyophilized.
How is a peptide characterised?
Characterisation normally combines chromatographic purity analysis (HPLC), molecular identification (mass spectrometry), and quantitative determination of how much peptide is present. Additional analyses such as endotoxin, sterility, residual solvent or counterion testing may be performed depending on the material.
Why does documentation matter?
Because a lyophilized powder looks identical regardless of what it contains, the analytical documentation associated with a specific batch is the only practical basis for evaluating identity, quantity and purity.