Type I collagen is present in connective tissue and bone where it makes up about 90% of the organic matri, Xenopus/Amphibian,. Type I collagen is produced from type-I procollagen by the proteolytic cleavage of N- and C-telopeptides, which are released into the circulation. The propeptides can be measured in serum as markers of the production of trype-I collagen. Elevated values of these propeptides are found in serum from patients with various metabolic or malignant bone diseases. Procollagen type I C-terminal propeptide (PICP) has a molecular mass of appro, Xenopus/Amphibian,imately 100 kDa. Its normal concentration in serum depends on age and se, Xenopus/Amphibian,. This antibody is specific for native human PICP. Cross-reactivity with PICP from other species has not been determined.