In recent years high-density arrays of specified DNA sequences have gained in popularity. Genomics and informatics are playing increasingly important roles as discovery tools in the basic biological sciences, and as diagnostic and rational therapeutic aids in the clinical arena. This publication was conceived during a microarray workshop organized by Dr. Gary Hardiman, BIOGEM (The BioMedical Genomics Microarray Laboratory) at the University of California San Diego (http://microarrays.ucsd.edu) and The Department of Bioscience at The University of California San Diego Extension. The book provides both an introduction and detailed overview of microarray technologies in academic and industrial settings. It examines evolving technology standards for microarray research, explores automation and instrumentation in the array laboratory, and discusses in detail the set up and operation of a microarray core facility. Novel detection methodologies are presented, and software tools that permit the rapid analysis of gene expression data are reviewed. The promise chip technologies hold for the fields of Agriculture and Drug discovery research is discussed. Emerging protein biochip technologies are reviewed and the challenges presented by proteome scale manipulation of proteins discussed in light of DNA arrays.