Dna analysis method and dna analyzer

Abstract

Disclosed is a DNA analysis method and a DNA analyzer whose signal intensity is not lowered even when a material at a higher density is measured. There is supplied dATP, dTTP, dGTP, or dCTP from a dATP solution vessel, a dTTP solution vessel, a dGTP solution vessel, or a dCTP solution vessel, and this causes an extension reaction of a double-stranded DNA immobilized to a bead, to yield pyrophosphoric acid. The pyrophosphoric acid is converted into a redox compound by the actions of a reagent and an enzyme contained in a reaction buffer in a reaction buffer vessel. The redox compound causes a variation in surface potential of a measuring electrode bearing an electrochemically active material immobilized thereto through an insulating molecule, and this variation causes a variation in drain current of a field-effect transistor electrically connected to the measuring electrode. Thus, the extension reaction is detected.