Microarray technologies and applications have evolved steadily with increasing content and better analytical methodologies. This compendium represents a cross section of the past five years of microarray methods and applications and their use in drug discovery and biomedical research. Expert contributors cover improvements in automation, new substrates for printing arrays, platform comparisons and contrasts, experimental design, data normalization and mining schemes, and epigenomic array studies. It also reviews electronic microarrays, comparative genomic hybridization, microRNA arrays, mutational analyses, clinical diagnostic arrays, protein arrays, and neuroscience applications.