Seaweed contains a special protein called a glycoprotein, which has an affinity for a specific sugar and is non-covalently bound thereto. The binding of the glycoprotein to the cell membrane sugar molecule causes cell sedimentation and is therefore a lectin. The glycoprotein is ubiquitous in terrestrial animals and plants and microorganisms, especially in legume seeds. The glycosidic protein plays an important role in the defense, growth, reproduction, nutrient storage and bio-symbiosis of the organism by identifying the characteristics of the sugar. The glycoprotein can also be applied to blood cell separation detection, drug carrier, production of immune antibodies and medical use of anticancer drugs.