Nucleic acid preparation (concentration and purification of various nucleic acid targets) from biological samples is essential for personalized and precision medicine. The adsorption of short-length DNA on graphene oxide (GO) layers was investigated and compared with that on silica surfaces. GO was efficiently coated on glass beads to be used more easily and spatially. Surface of the GO bead was confirmed by field-emission scanning electron microscopy. GO-coated beads were packed and the adsorption conditions of short-length DNA were optimized under various pH and flow rate conditions. The amount of adsorbed DNA was confirmed by real-time polymerase chain reaction and visualized using fluorescence microscopy.