Diagnosing complex diseases like cancer requires a dizzying array of expensive, often inconclusive and sometimes painful tests--biopsies into deeply rooted tumors or repeated brain scans that often aren't sensitive enough to pick up subtle changes that hint at abnormalities.
But what if all that information--the molecules that contribute to Alzheimer's, for example, or the antibodies that appear after nerves die in a Parkinson's patient--could be gleaned from a few drops of blood? That's the reality being engineered at institutions around the U.S., where researchers are parsing gases, hormones, nutrients, antibodies and other blood components to find potentially lifesaving information. Within a...