A new gadget to rapidly predict food poisoning is now available for food processing companies.
Called ImmunoFlow, the machine is no bigger than a personal stereo and is so small and light that its inventors ultimately envisage health inspectors using the device for on-the-spot checks.
Unlike today's tests, which can take many days, ImmunoFlow can work in 15 to 30 minutes.
Those saved hours could be critical when investigating an outbreak, says inventor Bart Weimer, a microbiologist at Utah State University in Logan.
"We can now detect bacteria more easily and with better sensitivity than existing commercial tests," says Weimer.
ImmunoFlow is so sensitive it can detect Salmonella, Listeria and E. coli O157 , even when there are only 100 cells per millilitre.
With the new device, investigators put a chunk of the suspect food or drink directly into the ImmunoFlow's testing chamber.
Solid food has to be pulverised first with a bit of water or buffer solution.
A battery-operated pump pushes the sample into the testing chamber.
Inside the chamber are hundreds of glass beads, each coated with millions of antibodies that stick to the kind of bacteria you are testing for, for example Salmonella.
The pump in the ImmunoFlow forces the liquid through the beads so the beads do not get clogged.
The investigator then adds another set of antibodies labelled with a luminescent marker that will bind to any antibody-bacterium complexes trapped in the chamber, giving off a telltale glow.
You cannot spot the glow without plugging the ImmunoFlow into a small machine called a photon counter.
Right now, the photon counter is as big as a PC, but Weimer's new company, Biomatrix Solutions, is aiming to make smaller, portable versions.
He hopes to begin marketing ImmunoFlow next May.