The Endotoxin from the gram-negative organism is -

Endotoxins heat stable lipopolysaccharides which form an integral pa of the cell wall of gram-negative bacteria. Their toxicity depends on the lipid component. They are released only by the disintegration of the cell wall. They cannot be toxoided. They are poor antigens and their toxicity is not completely neutralized by the homologous antibodies. They are active only in relatively large doses Diagrammatic representation of lipopolysaccharide has been given Above Ref: Ananthanarayan & paniker's Textbook of Microbiology 9th edition pg no 74