Purification of Plant Viruses

Abstract

Purification refers to the separation of virus particles from host components in a biologically active state. Purified virus is required for the production of antibodies, physical, biochemical and molecular characterization of virus isolates. Purification of virus involves several steps such as propagation of the virus in the host, extraction of sap, clarification, concentration and further purification. Purity of purified preparation can be checked through UV absorption spectra and its infectivity by inoculating to a susceptible host under optimal environmental conditions in an insect-proof glasshouse. Purification methods vary with different viruses, and there are no universal methods of virus purification. Procedures that are effective for one virus may not work with the other. Stable viruses that reach high concentration in their propagation hosts are easy to purify compared to viruses that are less stable and occur in low concentration in their hosts. In general herbaceous hosts (Chenopodium, Cucumis, Nicotiana, Petunia and Vigna) that have less of virus inhibitors are more suitable for purification than perennial hosts that contain inhibitors. In this chapter, detailed description of purification procedure for some of the important viruses is discussed.