ABSTRACT
This chapter presents a several general techniques that have proven useful in our own and other laboratories. It describes the key references for special techniques developed for invertebrate virus studies, and the rationale for choosing them. Since marine invertebrate viruses have been found to occur in lower concentrations and are more difficult to isolate than insect viruses, routine diagnosis has been based on Transmission Electron Microscopy observations that include the notation of shape, size, and presence or absence of envelope, and for some baculoviruses, the superficial structure of the nucleocapsid. A larva infected with nuclear polyhedrosis virus may appear whitish, swollen, larger or smaller than a healthy larva (signs) and show symptoms of constipation and loss of appetite. Higher speed centrifugations for longer times are required to sediment many of the small nonoccluded or nonocclusion body viruses. Many viruses are very fragile and require the use of buffers throughout the isolation and purification procedures.
