A new technique for detecting dangerous pathogens could lead to faster and cheaper diagnosis of disease and prevent food poisoning, say US researchers.The team claims their biosensor is accurate enough to identify different strains of disease-causing organisms in a blood sample in just 30 minutes, and at a fraction of the current cost. The researchers hope the test could soon be incorporated into an inexpensive hand-held device for use in the field and in the developing world.Current biosensors rely on a costly and time-consuming technique called gene amplification, which involves taking a piece of DNA from the sample and adding enzymes to make enough copies to allow the pathogen to be detected. It can take up to 48 hours for a positive result.By contrast, the new process exploits a natural matching technique. A sample of the pathogen-containing material to be tested – blood or food, for example – is placed in a test tube and heated in the presence of an enzyme to break down the cells and release their genetic material. Then a dipstick is placed into the mixture and left for a few minutes. Like in a pregnancy test, if a red line appears, the particular pathogen is present. The process takes just half an hour from start to finish.
