Protein biochips have recently gained a lot of attention as bioanalytical tools in the life sciences. The creation of such biochips has been made possible by the integration of scientific approaches and methodologies in microfabrication, organic interface chemistry, protein engineering, detection physics, and—last but not least—advances in microarrays and microfluidic dispensing technologies. This article reviews some of the current drop-on-demand technologies developed for printing biomolecular arrays, with an emphasis on proteins and the technical challenges associated with them.
