Our project is a novel bacterial method of DNA detection. We've developed a customisable, linearised, double stranded plasmid with two sticky overhangs. When the sticky overhangs come into contact with a target sequence, the binding of the DNA sequence to the overhangs circularises the plasmid. The circularised plasmid is then transformed into competent e. coli cells. Bacterial growth of green fluorescent colonies indicates a positive result, confirming presence of complementary DNA target sequence. This system could act as a cheap alternative to digital and real time PCR, as target DNA fragments are amplified in living cells without use of a costly PCR machine. This system could potentially be used as a diagnostic or screening tool for viral and/or bacterial infection such as Human Papilloma Virus, Mycobacterium tuberculosis. By improving sensitivity and specificity this system could also be used for detection of genetic mutations resulting in disease such as cystic fibrosis.