New gadget instantly tells if food is poisoned

The gadget, called ImmunoFlow, is only the size of a personal stereo and can deliver test results within 15 to 30 minutes. Currently, it can take food inspectors up to seven days before they get results because it takes at least 24 hours for any bugs from a sample to grow on a plate.

To begin with, the device will be used by food processing companies, but because it’s so small and light it could ultimately be used by health inspectors to conduct on-the-spot checks in restaurants and other food outlets.

Bart Weimer, the inventor and microbiologist at Utah State University, told New Scientist that the time saved by using the gadget could prove critical when investigating a food poisoning outbreak. “We can now detect bacteria more easily and with better sensitivity than existing commercial tests.”

With ImmunoFlow, investigators put a sample of the suspect food or drink into a testing chamber where glass beads, each coated with millions of antibodies, stick to the kind of bacteria that the food is being tested for.

By then adding another set of antibodies tagged with luminescent markers, which bind to any antibody-bacterium complexes, the investigators can tell whether the food is contaminated.

According to Mr Weimer, this process makes the device much more sensitive because in the past investigators had to rely on bacteria diffusing through a paper membrane covered with antibodies. However, bacteria are big and bulky, and often diffuse slowly and incompletely, making the tests less accurate.

Currently, a special machine the size of a personal computer is needed to detect the luminescent glow, but Mr Weimer’s company, Biomatrix Solutions, is aiming to make smaller portable versions.

Caroline Smith de Waal, from the Center for Science in the Public Interest, a nutrition and food safety advocacy group in the US, said, “A rapid test such as this could decrease the number of illnesses and deaths due to food-borne bacteria. We need to monitor food much more regularly than is being done today.”