finding the source of a foodborne illness outbreak can be difficult and time-consuming. but that could change thanks to spay-on DNA barcode from DNATrek. Scientists at the company can create solutions with unique DNA sequences and food-grade additive that can be sprayed onto produce. if this produce was implicated in a foodborne disease, a polymerase chain reaction test could analyze the suspected product and identify the grower, packer and/or shipper in about 15-20 minutes. The spay-on technology is said to cost about $1 for treating 1000 pounds of produce.