The immune system release specific antibodies when it encounters a virus. It can continue to produce those antibodies decades after an infection subsides. VirScan test detects those antibodies and uses them as a window in time to create a blueprint of nearly every virus an individual has encountered. The test, known as VirScan, works by screening the blood for antibodies against any of the 206 species of viruses known to infect humans.Researchers at Columbia University found a DNA-based blood test which can determine a person's entire viral history. This new test can lead to early detection of hepatitis C, certain autoimmune diseases and cancers. This new innovation test only for a single suspected virus. The study appears in Science.