Figure 7. Schematic representation of an antibody microarray system for monitoring protein profiles. Equal quantities of protein from test and reference cell lysates are labelled with either Cy3- (green) or Cy5- (red) NHS dyes. Unreacted dyes are removed by size exclusion chromatography. The proteins are loaded onto an antibody microarray and the microarray is analysed using a microarray scanner. Proteins are classified as upregulated, downregulated or unchanged, according to the colour intensity ratio of the two dyes. Reproduced from Sreekumar et al [52] with permission.