ABSTRACT An administrative supplement is requested to purchase an Advion Expression and Plate Express CMS system to support P20 GM104316: Discovery of Chemical Probes and Therapeutic Leads. The goal of this COBRE is to continue our efforts to develop molecular approaches for probing biology, to discover and apply new chemical biology tools for the study of biological pathways associated with disease, and to develop computational approaches for understanding small molecule interactions with complex macromolecular targets. The goal of this administrative supplement is to request funds for the purchase of an Advion Expression and Plate Express CMS system. The proposed instrument will be used by over 60 researchers and will be a critical tool for the COBRE custom synthesis lab which has already served over 20 groups on the UD campus. The Advion is a compact, single quadrupole ESI/APCI mass spectrometer (up to 2000 m/z) that offers unique capability in terms of sample introduction. The instrument will support major new capabilities for the COBRE community: (1) real-time reaction monitoring using the Plate Express enabling users to directly analyze TLC spots on a developed TLC plate. (2) Direct fraction checking of chromatography fractions using the ASAP probe will add MS-capability to the traditional flash, automated flash, and HPLC systems that are routinely used by more than 60 users.