DNA analysis such as PCR has become a powerful tool for food sanitation control due to its rapid detection capability with high sensitivity and selectivity. In this chapter, electrochemical DNA detection for E. coli and Salmonella via PCR and LAMP is introduced. We describe electrochemical measurements using electroactive DNA intercalating dye, bisbenzimidazole trihydrochloride for PCR, and methylene blue for LAMP. The peak current decreases when DNA is amplified, because the diffusion of dye-amplified DNA complex becomes slower on the electrode surface. Therefore, decreased peak current of indicator indicates DNA amplification, and the degree of reduction is related to the quantity of amplified DNA. The electrochemical-based DNA detection method presented here is a simple technique, using a screen-printed electrode and hand-held potentiostat. The screen-printed electrode is easy and inexpensive to produce in bulk, thereby offering disposable usage. This is advantageous for PCR and LAMP, because it can avoid contamination, which can be a major problem in these highly sensitive DNA amplification methods. The use of a hand-held potentiostat also makes this method suitable for the development of an on-site food testing system.