Few experiences invoke as much anxiety as a call from your doctor saying 'you need to come back for more tests.' Your imagination goes wild and suddenly a routine medical screening becomes a minefield of potential life-threatening diseases. It's highly likely, however, that you have fallen victim to a false positive -- a result that, despite the accuracy of the test, erroneously yields an affirmative result that points toward illness. To increase the accuracy of medical screening and reduce the incidence of false positives, scientists have designed a biomedical assay that eliminates the readout of these faulty results.