Our Sensor

The goal of our project is to design a biosensor to rapidly identify cattle known as super shedders. Super shedders are cattle that excrete extremely large numbers of E.coliO157:H7, a subgroup of E. coli referred to as Enterohemorrhagic E. coli (EHEC). EHEC organisms produce a toxin called Shiga toxin or verotoxin, which causes hemolytic-uremic syndrome (HUS) in humans and can be deadly.

We are building a DNA-based biosensor that specifically detects the gene called stx2 that is common among all EHEC organisms. Our device will be useful for the detection of not only the O157:H7 strain of E.coli but for the other EHEC strains as well. Click on the components above to learn more about their design and function. View our animation below to see how the system would actually work!

The FerriTALE System:

As seen in the video above our goal is to have a strip system that will be able to detect target DNA. This is accomplished by binding a TALE-Ferritin scaffold (a FerriTALE!) to a nitrocellulose strip. Once this strip is blocked, sample DNA will be run through the strip and captured by via a specific target sequence using our DNA binding TALEs. A second TALE attached to our reporter (Prussian blue ferritin or beta-lactamase) that targets another specific sequence on the captured DNA is run through this strip. After this step we add a substrate solution and if both TALEs have successfully bound the target DNA we will see a colour output on the strip.