Plasma is the straw coloured, viscous fluid constituting nearly 55% of the blood. It comprises of water (90-90%) and protein(6-8%).The major proteins present are fibrinogen, globulin and albumin. It also contains many minerals like  Na+, Ca⁺⁺, Mg⁺⁺, HCO3^–, Cl^–, etc. Glucose, amino acids, lipids, etc., are also present. Factors for coagulation or clotting of blood are also present in the plasma in an inactive form. Plasma without the clotting factors is called serum.