Collagen is the most abundant protein in our body, about 30% of total protein. Collagen is rich in bone, skin, tendon, ligament, cartilage, heart, eye, and so on. Synthesis of collagen protein is one of the most complicated process among the all human proteins. Many enzymatically posttranslational modifications involve the synthesis such as 3- and 4-hydroxyproline and 5-hydroxylysine. Some of hydroxylysine residues are additionally modified as galactosylhydroxylysine and glucosylgalactosylhydroxylysine. 4-Hydroxylation of proline increases the thermal stability of triple helical structure. These posttranslational modification reactions are essential to the biological function. Defection of these enzymes causes abnormality in bone and other organs. Due to the many posttranslational modifications and the large size of molecule, it is impossible to produce collagen molecules from recombinant expression with reasonable prices. With Nippi’s more than a half century of research expertise, we produce purified collagen from various kinds of animal tissues such as skin, tendon, lens capsule, and cartilage. Bovine, porcine, chick, tilapia are some of the animal sources. Product forms are solution, powder, or sheets of reconstituted fibrils. Types I, III, and IV collagens are on our catalog list. We also accept custom orders for other types and/or from other animal sources. Please contact us if you need specific types of collagen, or if you would like to order in bulk.