Professor Clemmer received a Ph.D. in Chemistry from the University of Utah and did postdoctoral work at the Himeji Institute of Technology (Japan) and Northwestern University before coming to IU in 1995. His research involves the development of novel instrumentation and methods for studying the structures of complex low-symmetry systems in the gas phase. These methods are being applied to several types of problems including the elucidation of fundamental issues associated with how a protein folds, as well as studies of complex mixtures of proteins the emerging field of proteomics. Clemmer's group is applying proteomic approaches to study aging and development using model organisms such as fruit flies.

Professor Clemmer and his group have published more than 100 scientific papers and their work has been recognized with several awards, including the Sloan, Dreyfus, NSF Career and later special creativity awards, as well as ACS Findeis and Fresenius Chemistry Awards. He has been a member of the US Defense Science Study group and is a scientific cofounder of Beyond Genomics, a company aimed at understanding the molecular mechanisms of diseased states.

He currently serves as the Robert and Marjorie Mann Chair, and the Chairperson of the Department of Chemistry at Indiana University. He is currently the Director of the Analytical Node of the Metacyte initiative and is a member of the Proteomics Research and Development group founded under INGEN. He is the recipient of the 2009 Tracy M. Sonneborn Award.