The discovery of Epstein-Barr virus (EBV) by Epstein, Achong, and Barr, reported in 1964 (Lancet 1:702703), was stimulated by Denis Burkitts rec- nition of a novel African childhood lymphoma and his postulation that an infectious agent was involved in the tumors etiology (Nature194:232234, 1962). Since then, molecular and cellular biological and computational technologies have progressed by leaps and bounds. The advent of recombinant DNA technology opened the possibilities of genetic research more than most would have realized. Not only have the molecular tools permitted the analyses of viral mechanisms, but, importantly, they have formed the basis for discerning viral presence and, subsequently, viral involvement in an increasing number of diseases. Though in every field of science the search for further knowledge is likely to be a limitless phenomenon, the distinct goal in EBV research, namely, to gain sufficient insight into the viralhost interaction to be able to intercept the pathogenic process, is beginning to be realized. Epstein-Barr virus research has effectively entered the postgenomic era that began with the sequencing of the first strains, cloned in the mid to late 1980s.Genome and Transcript Analyses.- Epstein-Barr Virus.- Analysis of Replication of oriP-Based Plasmids by Quantitative, Competitive PCR.- Genetic Analysis and Gene Expression with Mini-Epstein-Barr Virus Plasmids.- Construction of cDNA Libraries for the Analysis of the Structure of Complementary Strand Transcripts (CSTs).- Analysis of the Expression and Function of the EBV-Encoded Small RNAs, the EBERs, in Heterologous Cells.- Visualizing EBV Expression Patterns by FISH.- Viral Detection.- In Situ Detection of Epstein-Barr Virus DNA and Viral Gene Products.- Phenotype Determination of Epstein-Barr Virus-Infected Cells in Tissue Sections.- Detection of EBV Infection at the Single-Cell Level.- Detection and Discrimination of Latent and Replicative Herpesvirus Infection at the Single Cellƒ