Polysaccharides are large macromolecules made up of multiple monosaccharides joined together by covalent bonds called glysidic linkages. Glycogen is the primary polysaccharide demonstrated in animal/human tissue samples via histology staining technique.
The histochemical assessment of glycogen in tissue samples is often used to diagnose glycogen storage diseases. These diseases are characterized by an abnormal accumulation of glycogen in the liver due to inherited defects associated with liver enzymes. Detection of glycogen by histology staining techniques is also helpful in distinguishing between various types of malignant tumors including rhabdomyosarcomas and tumors of the Ewing's or PNET (primitive neuroectodermal tumor) family.