A viral test tells you if you have a current infection. There are different types of viral tests, including: Antigen Detection Test Viral antigens develop on the surface of cells infected with a specific virus. A viral antigen detection test is done on a sample of tissue that might be infected. Specially tagged (with dye or a tracer) antibodies that attach to those viral antigens are mixed with the sample. The tagged antibodies can be seen by using a special light (or other method). If the tagged antibodies are attached to the cells, the cells are infected with the virus. Viral Molecular Detection Test Using a sample of tissue or blood or other fluid, the test looks for the genetic material (DNA or RNA) of a specific virus. This test can show the exact virus causing an infection.