Periostin was originally isolated as an osteoblast-specific factor that functions as a cell adhesion molecule for pre-osteoblasts and is thought to be involved in osteoblast recruitment, attachment and spreading. Additionally, periostin expression has previously been shown to be significantly increased by both transforming growth factor beta1 (TGF-beta1) and bone morphogenetic protein 2 (BMP-2). Abnormal expression of periostin is also linked to angiogenesis and metastasis in epithelial tumors. Periostin up-regulation in cancers usually correlates with aggressiveness and/or poor survival. Sample Type: Cell culture supernatants, serum and plasma Intended Use: The human Periostin BioAssay? ELISA Kit is to be used for the in vitro quantitative determination of human periostin in cell culture supernatants, serum and plasma. Sensitivity: 15pg/ml Range: 78-5000pg/ml Specificity: Recognizes natural and recombinant human periostin. Has been tested on human periostin isoforms 1 and 2 (sho