Methods for subtyping and molecular comparison of human viral genomes

The development over the past two decades of molecular methods for manipula tion of RNA and DNA has afforded molecular virologists the ability to study viral genomes in detail that has heretofore not been possible. There are m any molecular techniques now available for typing and subtyping of viruses. The available methods include restriction fragment length polymorphism ana lysis, Southern blot analysis, oligonucleotide fingerprint analysis, revers e hybridization, DNA enzyme immunoassay, RNase protection analysis, single- strand conformation polymorphism analysis, heteroduplex mobility assay, nuc leotide sequencing, and genome segment length polymorphism analysis. The me thods have certain advantages and disadvantages which should be considered in their application to specific viruses or for specific purposes. These te chniques are likely to become more widely used in the future for epidemiolo gic studies and for investigations into the pathophysiology of virus infect ions.