Label free detection of NAPPA via mass spectrometry

Our research relates to the implementation of Nucleic Acid Programmable Protein Array (NAPPA) analysis by matrix assisted laser desorption/ionization mass spectrometry (MALDI MS). Such analysis enables interrogation of protein-protein interactions in a label- free manner by desorption and ionization of analytes (e.g., proteins synthesized from the immobilized cDNA and/or protein bounded to these). Mass spectrometry, in fact, has the unique advantage of being able to determine not only the presence but also establish the identity of a given ligand. However, the development of a MALDI MS-compatible protein microarray is complex since existing methods for forming protein microarrays do not transfer readily onto a MALDI target. Here we present a novel method for implementing a procedure to analyze protein contents on NAPPA protein microarrays using MALDI TOF mass spectrometry.