Avidin is a glycoprotein extracted from the egg white. The molecular weight is 60kD.Becouse each molecule consists of four subunits, so they can close combined with four biotin molecules. It plays an important role in immune mechanisms. Biotin can not work alone in the human body. It needs comprehensive regulation combining with other enzymes, amino acids and fat derivative. The biotin’s binding constants mean the binding capacity between it with other organic molecules.

Biotin, also known as vitamin H or coenzyme R. It is a water-soluble vitamin and also belongs to the vitamin B family. It the necessary material for the synthesis of vitamin C is the essential substance of the normal metabolism of fat and protein. Is a water-soluble vitamin necessary to maintain the body's natural growth and normal function of the body. Metabolism of fat and protein essential substances, and maintain normal growth, development and health of the necessary nutrients, can not through synthetic.

The efficacy of biotin for the treatment of arteriosclerosis, stroke, lipid metabolism disorders, hypertension, coronary heart disease and blood circulation disorders of the disease. Because glycogen gluconeogenesis, the combined effects of fatty acids, minoxidil and amino acid metabolism is a key regulatory elements, and were able to help the energy to play a role in promoting the synthesis of certain proteins; can help cells growth, manufacture of fatty acids, metabolism of carbohydrates, fat and protein, and contribute to the use of vitamin B group; to promote the health of sweat glands, nerve tissue, bone marrow, male gonads; to maintain the normal operation and growth of skin and hair, relieve eczema, dermatitis symptoms; the prevention of white hair and hair loss, to help treat baldness; ease muscle pain; there help for depression, insomnia; also involved in vitamin B12, folic acid, pantothenic acid metabolism; promote urea synthesis and excretion; improve the body's immune function .

The avidin more is extracted from streptomyces streptavidin. Biotin present in the egg yolk. Made of chemical derivatives, biotin NHS polyurethane with various types of protein, carbohydrates and enzymes of the size of the molecules form a biotinylated product. The combination of avidin and biotin, although an immune response, but high specificity, affinity, both a combination of extremely stable. It can be connected to an avidin molecule has four cosmetics material biotin molecule binding site. The more biotin molecules to form a similar lattice complex. Avidin and biotin with ELIS coupling can improve the sensitivity of the ELISA.

The application of affinity – biotin system in ELISA takes many forms. It can be used in indirectly package and the final reaction amplification. In addition, in the conventional ELISA, the HRP can also be used as the biotinylated antibody replacement. And then it will connect with the avidin - enzyme conjugates in order to enlarge the response signal.Source:http://www.cosprm.com