MALDI-TOF (matrix assisted laser desorption/ionization-time of flight) mass spectrometry (MS) is a state of the art method for the analysis of macromolecules such as proteins, peptides, and oligonucleotides. Recent improvements, such as delayed extraction, have had a profound impact on biological research. MALDI-TOF MS is now routinely used for high sensitivity, high performance analysis of proteins and other macromolecules, and can be used with samples from biological matrices. These uses and the features of the new generation of commercially available MALDI-TOF MS systems for dedicated use in biomedical research makes them a desirable addition to the existing shared biochemical resources within the Northwestern Drug Discovery Program. The availability of a MALDI-TOF mass spectrometer would significantly enhance the capability and productivity of NIH funded research of the major users and will allow some minor users to pursue research that was not feasible previously. The major users have prior experience with the use of MALDI-TOF MS in their funded research programs, but must use out of state resources. Currently there are no MALDI-TOF MS instruments at Northwestern University. Similarly, there is a lack of such instrumentation that is routinely available to academic-based biomedical researchers in the greater Chicago area. Therefore, funds are requested for a specific configuration of a commercially available MALDI-TOF MS instrument that is turn-key and state-of-the-art. The highly integrated and interactive user group with a documented record of sharing instrumentations and the institutional commitment make the focused use likely to succeed and the proposed instrumentation to have a high impact on multiple funded research programs.