The same magnetic technology that allows a computer hard drive to read and write data could be used to spot cancer in its earliest stages — something that, for many forms of cancer, means the success in treating it is far higher. Right now, researchers are experimenting with tagging specific proteins with dyes that allow them to be monitored for developing problems, but, as all proteins have a bit of fluorescence to them anyway, this method isn't thought to be the most accurate.
Magnetism, on the other hand, is attractive as proteins don't have a magnetic background, and can be seen more clearly. A startup venture out of Sunnyvale, California called MagArray is looking to commercialize a form of the prototype magnetic blood scanner being developed, which uses an array of magnetic sensors on a silicon chip to watch for proteins that have been tagged with magnetic nanoparticles.
Researchers at Stanford University are currently testing the potency of the magnetic scanning technique, and have found that it is far more sensitive when it comes to snooping out cancer. The scanner is based on the effects of giant magnetoresistance, which won a Nobel prize in 2007 for its discoverers, Albert Fert and Peter Grünberg.