Robert MacDonald Clegg (“Bob” Clegg), died of a recurrent cancer on October 15, 2012. He is survived by his wife Margitta, his sons Benjamin, Niels, and Robert, and by a large circle of friends, including those constituting an extensive scientific family of colleagues (Figure 1).
Bob was awarded a PhD in physical chemistry from Cornell University in 1974. His research on rapid chemical kinetics induced by pressure perturbation was conducted with Elliot Elson, an originator of Fluorescence Correlation Spectroscopy (FCS). The ensuing postdoc experience (with me) in the Department of Molecular Biology at the Max Planck Institute for Biophysical Chemistry led rapidly to the establishment of an independent unit with Bob as a Senior Staff Research Associate.
Bob exploited fully the unique facilities (technical and intellectual) provided by the Max Planck Society. He pursued numerous research topics, most often in very successful collaborations, and featuring kinetic and spectroscopic theories and techniques. Fluorescent probes provided the most important tools in his investigations of protein and nucleic acid structure, dynamics, and function. Inasmuch as intermolecular interactions were generally involved, Bob developed and applied extensively the theory and practice of FRET (Förster resonance energy transfer) as well as FLIM (lifetime imaging).
In the 1990s, Bob established a close working relationship with the pioneer of “biological fluorescence,” Gregorio Weber. This was intensified during a sabbatical stay in 1996 at the University of Illinois (UIUC) at Urbana-Champaign and ultimately led to “repatriation” with an appointment as Professor in the Departments of Physics and Bioengineering and as a member of the faculty of the Biophysics Program of UIUC. The academic environment was ideally suited to Bob's interests and temperament. Thus, in addition to his very successful research career, Bob was recognized as an exceptionally gifted teacher. One manifestation of this was the profound knowledge he developed and propagated via articles and presentations of the historical origins of fluorescence, microscopy, and—in particular—FRET. He applied these insights to a variety of systems extending from DNA helices and junctions to the photochemistry of skin.
Bob was a member of the Biophysical Society, the American Physical Society, FASEB, the Optical Society of America, and the American Chemical Society. In 2009, the Biophysical Society (Fluorescence Subgroup) awarded him the prestigious Weber Award for Excellence in Theory and Experiments in Fluorescence. Bob shared responsibility for the unique nationally funded research resource center, the LFD (Laboratory for Fluorescence Dynamics), established by Enrico Gratton in 1986 at UIC. The LFD promoted cutting-edge technology development, and greatly facilitated Bob's work on advanced FLIM instrumentation with biomedical capability.
Bob will be remembered not only because of his scientific contributions but also for his unique qualities as a warm, lively, and compassionate human being. He touched and enriched the lives of many…