One challenge when working with protein microarrays is the functional application of membrane proteins. Peptide microarrays are able to provide an alternative. They allow the proteins to be profiled as peptides for everything from individual proteins right through to the entire proteome of cells. In order to produce peptide microarrays, SPOT synthesis or similar methods are used for high density peptide microarrays. As a rule, the institute produces customized peptide microarrays, for which peptides are purchased and, following quality assurance, are immobilized in defined concentrations or series in multiple replicates. In contrast to proteins, peptides can vary enormously in their physicochemical properties, such as their isoelectric point or hydrophobicity. By using the available technology, the ideal/optimal conditions can be specified for each individual peptide, and minimum volumes of all peptides can be dispensed reliably and reproducibly onto a wide range of surfaces and structures.
Applications for peptide microarrays include the identification of antigen areas of surface proteins for bacterial germs and the identification of immunogens, epitope mapping and determination of the specificity of antibodies, serum profiling for the identification and validation of biomarkers, characterization of enzymes (e.g. target identification) or medical applications such as HLA profiling and the stratification of patients.