Final System

Our B. s. detector addresses the global problem of malaria misdiagnosis. It is a DNA-based detection tool using Bacillus subtilis as a chassis, taking advantage of innate homologous recombination mechanisms. The bacteria exists in spore form, simply hydrated for activation.

A small blood sample obtained from the patient is amplified using isothermal PCR, circumventing the need for hefty machinery to carry out thermocycling. This process is supplemented with a specialized Taq polymerase that is able to function well in the presence of blood.

The amplified product then travels to chambers containing B. subtilis engineered with pathogen-specific complementary flanking regions around the repressor in our genetic circuit. Thus, when B. subtilis is transformed with the product (via xylose induction) and target DNA is present, the flanking regions switch out the repressor. When the repressor is lifted, the reporter becomes active. This results in a colour output.

Thus, a colour output is given when the target DNA is present to cause de-repression of the reporter circuit.