Many NIH-supported investigators at UCLA are engaged in research that involves chemical synthesis. A critical aspect of synthetic work is the characterization of the reaction products of intermediate steps and the final product. Foremost among the methods used for characterizations is mass spectrometry, particularly where only small amounts of material are available. Many years ago the UCLA Department of Chemistry and Biochemistry established a mass spectrometry laboratory for the analysis of compounds by mass spectrometric techniques. At this time, there is a critical need to replace the very old mass spectrometers currently being used for a major portion of this type of analysis. Research descriptions from ten different research groups that make use of mass spectrometry are given with the following titles: 1) Synthetic Organic Chemistry; 2) Synthesis of Antitumor antibiotics and Alkylative Modification of Double- Stranded DNA; 3) Host Molecules that Complex and Catalyze; 4) Chiral Molecular Recognition and Principles of Carbohydrate Binding; Carriers for membrane Transport of AIDS-Targeted Drugs; 5) Singlet Oxygen Chemistry; 6) Boron-10-Labeled Antibodies in Cancer Therapy; 7) Stereoselectivities of Synthetic Organic Reactions; Intramolecular 10 and 8 Electron Cycloadditions; Theory and Modeling of Macrocyclization Reactions; 8) Synthesis via Metal Templated Radicals, Organometallic Stereoelectronics and Organometallic Electrocyclic Reactions; 9) Neuroreceptor Studies with Positron Emission Tomography; and 10) Nuclease Activity of 1, 10- Phenanthroline-Copper.