This paper describes microfluidic logic gates which use DNA and biological nanopores. Single-stranded DNA (ssDNA) can pass through αHL, a biological nanopore, incorporated in bilayer lipid membranes (BLMs), whereas double-stranded DNA (dsDNA) cannot. In this study, these passing and non-passing phenomena were applied as the binary system and logic gates. Two types of ssDNA were used as inputs, while the output was obtained by electrical signals across the nanopores, which recognizes whether ssDNA passed through the nanopores or not. NAND gate was successfully demonstrated by exploiting the mechanism. The proposed approach herein is significantly different from the conventional computation using DNA in the respect that electrical signals are directly obtained as the output, which drastically facilities the microfluidic system to connect to electrical systems for fast and accurate computing. In addition, it is not required to use fluorescence, enzyme or PCR in order to obtain outputs. We believe that this method leads to a rapid computing system using biomolecules.