Plasma proteins are the protein portion of plasma and a general term for the many proteins of plasma proteins. Plasma proteins can be divided into several components such as clear proteins, globulins and fibrinogen. Clear proteins have the smallest molecular weight of the three types of proteins, but are the most abundant in plasma. Normal globulin can play a certain role in immunoprotection. Plasma proteins are used as feed, nutritional supplements, and for the extraction of hemoglobin, hematoporphyrin derivatives, superoxide dismutase, and in a wide range of meat products.