useful for the research of various activities which high molecular hyaluronic acid does not haveHyaluronic acid is one of glycosaminoglycan, which does not include sulfate ester function, and it is isolated from the vitreous body of cow"s eye by Dr. Karl Meyer and his assistant Dr. John Palmer in 1934. Hyaluronic acid is constructed from disaccharide repeating units each consisting of a D-glucronic acid and N-acetyl-D-glucosamine, and it is said that the disaccharide repeating units are 10,000 or more in hyaluronic acid, which exist in a living body. Hyaluronic acid existin almost all of vertebrate, and distributed in all parts of body, especially distributed in vitreous body, synovial fluid, skin, egg cell, brain and so on. Biological features of high molecular hyaluronic acid is water-retention, maintenance of cell,differentiation control and so on.Recently, low molecular hyaluronic acid and hyaluronan oligosaccharide become known to have various activities which high molecular hyaluronic acid does not have. As shown in reference > recent many papers showthat by changing molecular weight the product exhibits quite opposite activities.For example, HA6 shows ""Induction of NO and MMPs in chondrocytes"". PG Research has isolated and purified these hyaluronic acid oligosaccharides (HA Oligosaccharides)as shown below to have endotoxicin-free Oligosaccharides, and has been presenting them for in vitro use.