non-gelling at 1% in 0.2 M KCl-solution Carrageenans are mucopolysaccharides from the cell walls of the red algae. They are anionic linear polymers composed of 1,3α-1,4β-galactans having one (κ-), two (ι-) or three (λ-) sulfates per disaccharide unit. In ionic solutions, κ- and ι-carrageenans self-associate into helical structures that form rigid or flexible gels, respectively. λ-carrageenans do not form helices and are non-gelling. Carrageenans are used commercially as thickeners and stabilizing agents.Carrageenans are used to suppress immune response in vivo and in vitro via mechanisms believed to involve selective cytopathic effect on macrophages. Non-gelling λ-carrageenan is used to induce inflammation and inflammatory pain in the rodent hindpaw or air pouch models. More recently carrageenan has been injected directly into the joints of rodents to model arthritic pain and inflammation. non-gelling at 1% in 0.2 M KCl-solution Carrageenans are mucopolysaccharides from the cell walls of the red algae. They are anionic linear polymers composed of 1,3α-1,4β-galactans having one (κ-), two (ι-) or three (λ-) sulfates per disaccharide unit. In ionic solutions, κ- and ι-carrageenans self-associate into helical structures that form rigid or flexible gels, respectively. λ-carrageenans do not form helices and are non-gelling. Carrageenans are used commercially as thickeners and stabilizing agents. Carrageenans are used to suppress immune response in vivo and in vitro via mechanisms believed to involve selective cytopathic effect on macrophages. Non-gelling λ-carrageenan is used to induce inflammation and inflammatory pain in the rodent hindpaw or air pouch models. More recently carrageenan has been injected directly into the joints of rodents to model arthritic pain and inflammation.