Carrageenans, alginates and agaroses, with other macroalgal polysaccharides, have biomedicine applications. The polyanion category of microbicides includes the carrageenans. These compounds include fucoidans, carrageenans and ulvans that are used for their beneficial properties. Many red algal species produce different types of carrageenans during their developmental history. Carrageenans are large, highly flexible molecules that form curling helical structures.