A microarray is an arrangement of miniaturized test sites or “spots” on a surface. Each spot is usually no more than 250 micrometers in diameter and contains biological molecules—usually DNA or protein—which act as probes for a test sample applied to the array. The surface may be a glass slide, a plastic plate with wells or a polymer bead. The microarray format allows many tests or experiments to be performed simultaneously, in parallel, leading to the generation of huge amounts of biological information for the application of only a tiny amount of sample. Microarrays are often also known as “biochips”. The purpose of this TriMark Publications report is to describe the specific segment of the microarray market aimed at analysis of proteins and DNA. Protein microarray applications include: 1) expression profiling; 2) serum-based diagnostics; 3) protein-protein binding assays; 4 drug-target binding; and 5) receptor epitope binding. It examines the market for DNA and protein array testing equipment and supplies using screening reagents and instruments for analysis of individual components in blood, serum or plasma. It defines the dollar volume of sales, both worldwide and in the U.S., and analyzes the factors that influence the size and the growth of the market segments. Also examined are the subsections of each market segment, including the research labs, hospital labs, and commercial laboratories. Additionally, the numbers of institutions using this type of testing and the factors that influence purchases are discussed. The report surveys almost all of the companies known to be marketing, manufacturing or developing instruments and reagents for the protein array market in the U.S. Each company is discussed in depth with a section on its history, product line, business and marketing analysis, and a subjective commentary of the company’s market position.