The Year 12 Biology students were faced with the challenge of attempting to detect the presence of pathogenic Escherichia coli bacteria (E. coli) in two food samples, one of which was the ‘suspect’ in causing food poisoning.  

For this investigation students ran a process referred to as polymerase chain reaction (PCR). This process amplified DNA from the two food samples, and the samples of a pathogenic and a non-pathogenic E. coli bacteria.  This amplification process lead to the production of 1073,741,824 copies of DNA. These copies were then put through a process called electrophoresis in which DNA was separated into their specific banding.  By matching the bands formed from the DNA samples students were able to conclude the food sample that contained the “culprit”.