Scientists have developed a better sniff test for that plate of leftovers that's been hanging out in your fridge. Researchers from the Korea Advanced Institutes of Science and Technology are using lasers (the jury is out on whether they're of the "friggin'" variety or not) to determine just how much bacteria is crawling all over your stored food. MIT Technology Review says that by shooting a red, coherent laser at chicken breast coated with E. coli and Bacillus cereus, the Korean scientists were able to detect changes in laser refractions, indicating the bacteria's presence.
Using a camera operating at 30 Hz, the researchers clearly identified the contaminated meat, but couldn't separate one contaminant from the other. Unlike other advancements in the area, MIT reports that this process is the sort of thing that could go on food production lines or even in a refrigerator, requires no physical contact and works on foods under cellophane. This isn't a silver bullet for food poisoning, though: It can't see viral contaminants, or the toxins produced by bacteria that stick around even after the bugs die off.
Should you not have a red, coherent laser and a camera that fires 30 times a second, there's always the low-tech rule of thumb: When in doubt, throw it out.