Objective To replace the imported vacuum pump with a Chinese-made instrument using a micro-ELISA negative pressure pump,to further extend the life of the machine.Methods Electric aspirator(YB.Dx23D) was used as source of negative pressure to connect with barrels of waste and the vacuum-phase of imported enzyme immunoassay instrument.The circuit was transformed,and the host matched the load,so the host and negative pressure pumps worked simultaneously.Results Compared with other aspirators,the modified electric aspirator YB.Dx23D has low-noise ratio,high negative pressure,vast flow,small volume,and mobile function.Conclusion The modified aspirator YB.Dx23D electric instrument is well used in washing ELISA plates and the effective use of waste water.Meanwhile,it can be applied to other necessary suction negative pressure(vacuum) equipment.