More than 26 distinct collagen types have been identified in mammalian tissues. The collagen molecule is composed of three alpha-chains and is unique regardless of the type of collagen. The amino acid sequence is characterized by Gly-X-Y, where X is Proline and Y is Hydroxyproline, to form a stable triple helical conformation. This structure is highly resistant to proteolytic degradation, heat, various chemicals, and physical stress. Tissue contribution of individual types of collagen is also unique. For example, type I collagen is most abundant in various connective tissues such as skin and bone. However, collagen composition in articular hyaline cartilage and the vitreous body of the eye lack type I collagen and is composed of type II (80-85%), type IX (3-5%), and type XI collagen (5-10%). Since the different types of collagen share similar amino acid sequences and three dimensional structure, it is difficult and impossible to identify the collagen types in tissues by ordinary chemical or histological evaluations. To identify unique collagen types in hyaline cartilage, Chondrex provides two cocktails of monoclonal antibodies, one is specific to type II collagen and other is specific to type IX collagen.

The monoclonal antibopdies to type II collagen recognize the conserved epitopes of various species of type II collagen such as human, monkey, porcine, bovine, rat, mouse, and chick, and cross-reacts to all these species of type II collagen by more than 95%. Thus, this cocktail can be used for immunoblotting and immunostaining of tissue sections from these species.

The monoclonal antibody cocktails to type IX collagen recognize the conserved epitopes on the low molecular weight fragment of human, bovine, rat, and chick type IX collagen. Thus, this cocktail can be used for immunoblotting and immunostaining of tissue sections from human, bovine, rat, and chick.

Note: None of these monoclonal antibodies cross-react to type I, type II, and type XI collagen. The cross-reactivity of type IX in other species has not been studied.