A protein microarray (or protein chip) is a high-throughput method used to track the interactions and activities of proteins, and to determine their function, and determining function on a large scale.[1] Its main advantage lies in the fact that large numbers of proteins can be tracked in parallel. The chip consists of a support surface such as a glass slide, nitrocellulose membrane, bead, or microtitre plate, to which an array of capture proteins is bound.[2] Probe molecules, typically labeled with a fluorescent dye, are added to the array. Any reaction between the probe and the immobilised protein emits a fluorescent signal that is read by a laser scanner.[3] Protein microarrays are rapid, automated, economical, and highly sensitive, consuming small quantities of samples and reagents.[4] The concept and methodology of protein microarrays was first introduced and illustrated in antibody microarrays (also referred to as antibody matrix) in 1983 in a scientific publication[5] and a series of patents.[6] The high-throughput technology behind the protein microarray was relatively easy to develop since it is based on the technology developed for DNA microarrays,[7] which have become the most widely used microarrays.