With increasing viral infections in patients immunocompromised due to cancer therapies, organ and bone marrow transplantations and HIV infection, the use of antiviral therapeutics has increased, and with this the development of antiviral resistance. As the incidence of antiviral resistance increases, the need for a simple and rapid method to determine the susceptibility of a virus becomes more important. Development of such a method is in progress using a 96-well microtiter plate containing a particular cell culture and centrifugation- amplification (shell vial method) of the particular virus in the microtiter plate. Detection of the virus in the presence of various dilutions of the antiviral agent will first be performed using an enzyme immunoassay format, with subsequent determination of an lD50 indicating susceptibility or resistance. Future efforts will utilize hybridization of viral DNA with a DNA probe and the incorporation of a non-radioactive detection system in a dot-blot hybridization format.