2-B-P-100 〇杉山 黎¹、林 克儀²、中村 史雄^3,4、櫻井 隆⁵、五嶋 良郎³、山下 直也^1,3,5 Sugiyama Rei¹, Ke-Yi Lin², Fumio Nakamura^3,4, Takashi Sakurai⁵, Yoshio Goshima³, Naoya Yamashita^{1,3,5 1}神奈川工大・応用バイオ、²カイオム・バイオサイエンス、³横浜市立大・医、⁴東京女子医科大・医、⁵順天堂大・医 ¹Dept. Applied Biosci., Kanagawa Inst. Tech., ²Chiome Bioscience, ³Dept. Mol Pharmacol and Neurobiol, Grad. Sch. Med., Yokohama City Univ., ⁴Dept. Biochem, Tokyo Women's Medical Univ., ⁵Dept. Pharmacol., Juntendo Univ. Sch. Med. Extracellular soluble signals that control several aspects of neuronal development are known to play a critical role in maintaining neuronal function and homeostasis in the mature nervous system. Abnormal expression and/or secretion of these molecules are therefore thought to be associated with the onset of various types of neurological disorders. It has been reported that the expression of Semaphorin 3A (Sema3A), a secreted type of repulsive axon guidance molecule, is impaired in several neurodegenerative disorders. However, due to the lack of a reliable Sema3A antibody, our knowledge about Sema3A expression in the adult brain is still limited. Here we report the identification of a pair of Sema3A monoclonal antibodies for the sandwich ELISA assay using the Autonomously Diversifying Library system. Our Sema3A monoclonal antibodies recognize the blade 3-4 or the blade 5 of Sema domain, respectively. We can measure the concentration of recombinant human Sema3A in the range of 0-100 pM by ELISA. The specificity of this assay was confirmed by using the embryonic brains from sema3A deficient mice as a negative control. Moreover, this assay could measure Sema3A concentration in Tris buffered saline- and SDS-soluble lysate obtained from the adult mice brains. These data suggested that our ELISA assay is a reliable tool for the validation of Sema3A as a biomarker in neurodegenerative disorders.