Rapid Test Detects Tainted Milk

CARBONDALE, Ill.Researchers from Southern Illinois University Carbondales College of Agricultural Sciences and North Carolina Agricultural and Technical State University have developed a rapid test that reveals the presence of toxins in milk in just a few hours. This breakthrough may be an important step toward improving the safety of the countrys dairy supply.

Scientists focused on the bacteria that ferment lactose, producing lactic acid as they go. Researchers began in 2008 with a few bacterial strains they already had and cyanide. Experiments showed the toxin not only could slow or stop lactic acid production, but the effect increased with the toxic load. Further, the effect appeared in less than four hours.

Researchers then added purple dye to milk samples containing both toxins and bacteria and to samples containing only bacteria. After eight hours, dye in the non-toxic milk turned yellow, indicating the presence of increased lactic acid, while dye in the toxin-laden milk retained its original purple.

This kind of color test could be performed by farmers themselves, said the researchers. They could add the bacteria and the dye to a sample, leave it alone for a little while and then come back to see if there is any change in the color. If there isnt, there are problems with the milk. The test wont tell us what sort of toxin is in the milk; it only tells us there is something wrong. Its like an alarm.