Piston of nucleic acid extracting cartridge

The present invention provides a piston of a nucleic acid extracting cartridge, the piston comprising: a cylindrical upper body having a hollow; a lower body coupled to one end of the upper body and comprising two ports arranged to be spaced apart from each other by a predetermined angle; a control rod module coupled to the other end of the upper body to seal the other end and moving upward/downward along the hollow; and a rotation adjusting module coupled to a shaft of the lower body so as to transfer a driving force to the lower body.