Neutral Loss | Electron-transfer dissociation (ETD) is a technique for fragmenting proteins and peptides. In addition to generating backbone cleavage, ETD can produce neutral losses from the side chains of amino acid residues. This image depicts the ejection of small neutral loss fragments from a small peptide, induced by ETD. Illustration created purely from scratch with Adobe Illustrator. All components were created without the assistance of any other instrument, tools or resources.