Differentiation of lambda carrageenans from Rhodophyta with immunological and spectroscopic techniques

KCl soluble carrageenans from sporophytes of two Gigartina species were differentiated from those of Chondrus crispus Stackhouse, Iridaea cordata (Turner) Bory, Rhodoglossum californicum (J. Ag.) Abbott, and two Petrocelis species by their failure to precipitate on immunodiffusion against either of two absorbed anti- lambda -carrageenan antisera. The carrageenans have been analyzed by infrared spectroscopy, and on this basis it is postulated that the antibody preparations recognize sulphate on C-6 of the carrageenans. The Gigartina carrageenans appear to lack sulfate at this position.