Water, water everywhere,
NATURAL disasters such as tsunamis often leave local water sources tainted with harmful bacteria, and existing tests for contamination take as long as three days to produce a result.
Now a $30 test that takes just half an hour has been developed at Australia’s Environmental Biotechnology Cooperative Research Centre near Sydney. Antibodies attached to tiny magnets
are added to the water so when bacteria in the sample bind to the antibodies, they can be concentrated with a magnet.
The sample is then injected into a “bubble pack” containing chemicals that break open the bacteria, allowing their RNA to escape. An enzyme specially modified to work at close to room
temperature then amplifies the RNA so that it can be detected by an electrochemical sensor even if very few bacteria are present.