Protein microarrays involve applying proteins to modified object substrates (slides) and immobilizing them. To do this, the corresponding proteins can either be recombinantly produced from cDNA or expression libraries, or protein microarrays based on DNA microarrays can be produced by means of in-vitro transcription/translation on demand.
The protein microarrays produced can be used for a large number of different applications. These microarrays are most frequently used for the identification of interactions. Along with protein-protein interactions, this also allows the examination of interactions between the immobilized proteins with small molecules, e.g. ATP and medications, as well as the influence of cofactors, the salt content and pH on interactions with lipids and carbohydrates.
The challenge involved in production is that all proteins need to be immobilized uniformly and as functionally as possible. There are a large number of different techniques available to do this. The spectrum ranges from adsorption on nitrocellulose to covalent linkage, for example on epoxy-modified surfaces or by means of click chemistry, as well as immobilization using affinity tags or antibodies.
The range of available technologies and the many years of expertise allow many classes of proteins to be applied to a wide range of surfaces, and to be used for analysis.