Another E.Coli outbreak means bags of lettuce could prove to be painful. After a sample of dole's hearts delight package tested positive in Canada, expect the emptying of shelves.

"E.Coli will generally find its way into the food chain," said Ed Bradley.

Bradley is the Vice President of food safety at Neogen Corporation, a company that sends testing kits to food manufacturers to test for bacteria like E.Coli. The bacteria can develop from water runoff at farms, and also from harvesting and packaging equipment, which spreads E.Coli to non contaminated greens.

"We're buying more and more product that's packaged in a central location, where over ten years ago, most of our lettuce came in a head of lettuce," said Bradley.

There have been no reports of any illness thus far.

The problem has MSU's School of Packaging trying to bag an answer.

"A lot of research is going in trying to overcome the problem," said Maria Rubino, Assistant Professor at Michigan State University's School of Packaging. "We are designing new devices that help to distribute a specific bacteria-like gases within the packaging system.

Even with all the research, Rubino says there's only so much good packaging can do-- and it may have food manufacturers changing the way grow their produce.

"There's many factors that need to be considered. Everything from growing the plants all the way to how its going to be processed during harvesting, cleaning, the proper handling of the product," said Rubino.

Factors to keep you eating your greens.