The classic method of monoclonal antibody preparation was used [12, 13] . In brief, selected one mouse that had high sensitive activation to renalase protein, harvested the spleen, then extracted spleen cells and myeloma cell line SP2/0, and then performed cell fusion with 50%(w/v)polyethylene glycol in a 50 ml centrifuge tube (Corning, New York, USA). Following the cell fusion, cells were subjected to centrifugation and transferred to 96-well plate, and then with HAT added, cell selection was performed. Ten days after the cell-fusion, cells selection was performed with selecting ELISA positive holes.