The titer of antibody from mice serum was tested before the cell fusion. One mouse with high titer was selected as spleen cells donor and cell fusion was done with cell line SP2/0. The serum titer of anti-renalase was 1:32000 and the titer of normal mouse was below 1:1000. After 3 cycles of cloning, two hybridoma cell lines were obtained. Culture supernatant was collected and ascites was prepared. Analysis of culture supernatant showed an antibody titer of 1:128000, and an antibody sub type IgG1/k. Titration ELISA of purified anti-renalase monoclonal antibody was over 1:512000, higher than that of poly-serum titer 1:128000. Western blotting was performed by using prokaryotic expressed renalase protein as the sample and the prepared anti-renalase monoclonal antibodies as primary antibodies. The results showed the recombinant renalase protein can be recognized by the monoclonal antibody (Fig. 2) . Renalase's expression in renal tissues can be detected by immunofluorescence Indirect immunofluorescence testing was conducted by using anti-renalase monoclonal antibody. The results showed that renalase expressed in cytoplasm of glomerular mesangial cells (Fig. 3A) . And renalase can also be detected for its expression in cytoplasm of tubule epithelial cells (Fig. 3C ).