The Mass Spectrometry Shared Resource provides critical services to Cancer Center members whose research relies on structure determination of a variety of different molecules. Services currently provided by the Shared Resource include high and low resolution fast atom bombardment (FAB) ionization, high and low resolution electron ionization (El), and high and low resolution chemical ionization (CI). After the installation of. two new instruments, mass spectrometry services will be expanded to include high and low resolution electrospray ionization (ESl), tandem mass spectrometry (MSIMS), and LC-MS capabilities. Except for low resolution El and CI analyses, the Shared Resource is the only location at Purdue University where the above mass spectrometry techniques can be performed. This facility is overwhelmingly utilized for cancer-related research and derives considerable benefit from its participation in the Campus-Wide Mass Spectrometry Center (CWMSC), which insures service to the entire cancer research community at Purdue University. The Mass Spectrometry Shared Resource, in conjunction with the CWMSC, has several goals including: I) coordinating the operation and maintenance of mass spectrometers used for routine analyses, 2) providing research groups working on cancer related problems with access to all of the mass spectrometry technology on campus, 3) increasing awareness of the opportunities for problem solving by mass spectrometry, 4) coordinating the acquisition of new instrumentation as needs arise, and 5) developing new methods required to analyze user samples. Cancer Center members derive considerable benefit from the instrumentation and expertise provided by this Shared Resource and its personnel.