Six weeks old BALB/c mice (Shanghai Experimental Animal Center of Chinese Academy of Sciences) were kept in SPF grade animal room. Animals were used according to the feeding and utilization guidelines prescribed by Chinese Academy of Science. Animal immunization was done as per the recommended methods in the literature [11] : 100 mg plasmids (100 ml sterile PBS, pH 7.4) was given intramuscularly in the quadriceps. Immediately after the injection, electric impulse stimulation was given with ECM830 (BTX, Holliston, USA). Stimulation parameters were square wave, 100 V/50 ms, positive and negative impulses given three times each, with an interval of 1 second. A total of three injections were given with an interval of 3 weeks. Three weeks after the last injection, cell fusion was carried out. A shot of intra-abdominal booster of recombinant renalase protein was given three days before the cell fusion. 10 days after the third injection, blood was withdrawn from the orbit, kept for 1 hour at the temperature of 37uC, followed by 24 hours at 4uC, and then centrifuged. Upper layer of colorless or pale yellow serum was collected and stored at 220uC for further use.