This Small Business Innovation Research Phase I project proposal is focused on the development of a commercial instrument capable of rapid, high-throughput identification of peptides based on matrix-assisted laser desorption ionization, ion mobility spectrometry, photodissociation, and time-of-flight mass spectrometry technology. The implications of the proposed instrument are vast but the most significant contribution is a time reduction in the identification of peptides from mixtures (e.g., protein digests). The keys to the project are the use of an ion mobility spectrometer as the separation device and a laser for ion dissociation. For example, an ion mobility spectrometer is capable of separating peptide mixtures with a resolution of 50-100 on the millisecond time-scale. This is a significant saving in time compared to the tens to hundreds of minutes needed by HPLC. The incorporation of a laser to induce fragmentation provides mass and chemical selectivity not afforded by other fragmentation means such as collision-induced dissociation or surface induced dissociation. Use of a laser also eliminates the need for numerous ion optical devices for fragmentation and focusing of ions, thereby simplifying the overall instrument design. The instrument can also be extended to other areas of chemical research simply by adjusting the laser wavelength.