The Detoxi-Gel™ Endotoxin Removing Gel uses immobilized polymixin B to bind and remove pyrogens from solution. Thepolymixins are a family of antibiotics that contain a cationic cyclopeptide with a fatty acid chain. Polymixin B neutralizes thebiological activity of endotoxins by binding to the lipid A portion of bacterial lipopolysaccharide. Studies performed byKluger et al. indicate that the immobilized polymixin B inactivates some but not all endotoxins.1The immobilized polymixin B gel is a stable affinity matrix that resists leaching of ligand into the valuable preparation.Making use of an affinity support permits easy cleanup of buffers, cell culture media, solutions containing macromoleculessuch as proteins, and pharmacologically important components. Detoxi-Gel™ Endotoxin Removing Gel also has been usedto remove endotoxin from nucleic acid (DNA) samples.