An analytical maestro shifts focus Ed Yeung is not really retiring, just going on a “permanent sabbatical”.
he many research accomplishments of Iowa State University professor Edward S. Yeung have bridged the analytical, physical, and biological sciences. How one career could span such areas as laser-based detectors for LC, CE, surface science, nonlinear spectroscopy, single-cell and single-molecule analysis, chemometrics, polarimetry, biotechnology, and DNA sequencing is awe-inspiring. “The breadth of this record is truly amazing and serves as a tour de force in the field of analytical chemistry,” observes Donald R. Bobbitt, a former student of Yeung’s who recently became provost and vice president for academic affairs at the University of Texas Arlington. But Yeung’s portfolio goes well beyond the research and scholarship typical of a university professor. His career has blended research, inventions and patents, a start-up venture, and four R&D 100 Awards. At the same time, he has also served as educator, mentor, and investigator at Ames Laboratory, a U.S. Department of Energy research facility that is run by Iowa State University. During his term as an associate editor of Analytical Chemistry from 1988 until he retired in August of this year, Yeung’s contribution has been “enormous,” says Editor in Chief Royce Murray. Yeung was one of the first associate editors of AC and helped shape it into its present incarnation. According to Murray, Yeung’s broad knowledge of analytical chemistry made him an invaluable asset, and his rigorous standards helped the journal maintain its integrity as a leading analytical chemistry publication. Yeung “was fairOhard-nosed, but fair,” says Murray. “And so I will miss him. He is really a stalwart of the Analytical Chemistry journal and of the community. We all owe him a debt of gratitude.” 7184
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Yeung shows off his skill on the violin.
Now, as he retires from his positions at the university and the journal, Yeung prepares to refocus his energies and fulfill other lifelong dreams.
The life and times Yeung spent his childhood in Hong Kong but left after finishing high school. “The reason I came to the U.S. is that I wanted a broader education than what was possible in Hong Kong in science,” says Yeung. “In Hong Kong, if you major in chemistry, you only study chemistryOmaybe physics and mathObut not anything else. I went to Cornell [University]Oto their College of Arts and SciencesOand got a more general education.” After doing some undergraduate research at Cornell, Yeung decided that the lab was for him. He joined C. Bradley Moore’s group at the University of California Berkeley, obtained his Ph.D., and never looked back. “When I graduated, I knew I wanted to go into academics,” he says. “When a position opened at Iowa State... with an Ames Laboratory connectionOand the way
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that I understood [it], Ames Lab had a certain degree of freedom in longerterm type of researchOI took the job at Iowa State and never regretted it.” During his long tenure at Iowa, he mentored dozens of young scientists. “He was just beloved by his students,” says one of Yeung’s former students, Kristy Skogerboe, a professor at Seattle University. “He’s a shy individualOhe’s not supergregarious, but he did have a twinkling sense of humor. And he understood what it was like to be a student and working hard and needing to balance research and having fun.” That twinkling sense of fun would emerge at the annual group picnics. “We would all get together once a year down at one of the lakes in Iowa,” recalls former Yeung graduate student and current University of Washington professor Robert Synovec. “We’d get up the morning of the picnic before it was light, and we’d drive down to the reservoir and go fishing for a few hours before the picnic was going to start.” He adds that reminiscences of a few wayward casts brought peals of laughter to a recent gathering of former group members. Michael Sepaniak, who is a member of the Yeung academic clan and is now a professor at the University of Tennessee, recalls that later on at the picnic, the fun would turn to water skiing. And when Yeung was at the helm, he was known to give the more advanced skiers a spirited ride around the lake. Other facets of Yeung have been known to delight and surprise: for example, his expertise on the violin. When a crowd of former students and colleagues gathered this year in May to celebrate Yeung’s birthday at the same little restaurant in Ames they had frequented some 25 years earlier, they encountered a group of music students who needed one more violinist to make
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chemistry laboratories,” Yeung says. It “may not say ‘capillary electrophoresis’ on the sequencer, but the technology [based on our publication] is there.” The 1994 paper demonstrated multiplexed DNA detection in 96 capillaries; today, the commercial instruments contain 16⫺384 capillaries in different versions, but the concept is the same. From Yeung’s point of view, seeing a technology move out of the basic research lab and into wide practice is gratifying “because it’s not just [about] the number of papers and number of citations; you now actually have something that did get accepted by the community and is used in thousands of instruments every day.” The original CE technology used a fluorescence detection method, but a similar approach that uses absorption detection led to the formation in 2000 of Yeung’s start-up company, CombiSep. Fluorescence detection methods work well for DNA and proteins, but for nonfluorescent compounds, such as some pharmaceuticals and fine chemicals, a different detection method is required. “We knew this was a need because 70% of... molecules do not fluoresce and are not easily derivatized to fluoresce,” says Yeung. It took ⬍1 year from the hiring of the first employee to sell the first unit, because Yeung’s group had all along envisioned how to make the instrument rugged and sensitive enough for general use. “Absorption is much less sensitive inherently, compared to fluorescence, so all the optics [had] to be designed in such a way as to optimize signal to noise,” says Yeung. “The idea is fairly straightforward, but to do it to the level of sensitivity that is useful was quite a challenge.” CombiSep’s instruments are now in place in many pharmaceutical and biotechnology labs. The company merged with AATI in 2007 and will launch three new products in the coming year.
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a quartet. Yeung stepped up with a little Eine Kleine Nachtmusik. “He’s very good,” exclaims Homing Pang, a former postdoc who is now director of R&D at Advanced Analytical Technologies, Inc. (AATI). “It’s a surprise to hear how well a chemist interprets the music.” Yeung enjoys going to concerts and listening to classical music and has been known to take his violin along on international visits to make music with colleagues. He has played the instrument since childhood. “I started too late,” says Yeung a little wistfully. “I started when I was 11; that’s why I could never become a professional musician.” Music’s loss has been analytical Yeung’s musical abilities extend to karaoke as well. chemistry’s gain. was a major innovator in the field, so I His former graduate students all started keeping track of his papersOin fact comment on Yeung’s dedication and I started looking forward and worrying if I quiet, respectful manner. “He is softdidn’t see a paper within a couple of spoken, but at the same time that doesn’t mean that he’s easygoing by any weeks,” says Callis. “What was Ed up to? means,” says Synovec. “He always [I thought it] must be something espeworked very hard himself and was a cially fantastic if it was going to take him wonderful role model and mentor to all that long to get the next paper out!” of the group members.” Yeung has managed to keep more than Former student William G. Tong, a few other analytical chemists on the now a professor at San Diego State Uni- edges of their seats, waiting to see what he versity, observes that Yeung’s many inwould come up with next. “I continue to ventions “teach us how to successfully look forward to reading his papers describbridge chemistry and physics and how to ing one great concept after another that perfectly interface chemistry and materialized into novel methods for anabiology.” And, he adds, “Those of us lytical chemistry,” says Tong. “His ideas who teach after leaving his research and novel analytical methods are so fresh, group in Ames appreciate him even sophisticated, and eloquent and yet [are] more as a teacher and mentor.” described [so] plainly that most scientists feel they could apply his inventions immediately in various far-ranging fields. It is On the edge of their seats how quickly he can follow one great inYeung’s colleagues also laud his work. “Ed vention after another that is so impressive does what I think analytical chemists to us.” should do, which is to take sound physical Of his many ideas and inventions, principles and turn them into viable anaYeung’s work on simultaneous monitorlytical instrumentation,” says University of ing of DNA fragments by multiplexed CE Washington chemistry professor James B. (Anal. Chem. 1994, 68, 1424⫺1431) has Callis. “He is one of the most creative had perhaps the broadest impact. The minds in all of analytical chemistry.” technology has been licensed to Applied Callis recalls that he first encountered Biosystems, which uses it in its DNA-seYeung as a result of their mutual interest quencing instruments. “It’s basically the in detector modules for chromatography. workhorse of a lot of genetics and bio“It soon became apparent that Ed Yeung
Finding diamonds Yeung’s curriculum vitae sparkles with a constellation of honors and awards,
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of the job I like most and the part of the job I think I should do more [of]. I want to think at a bigger-picture level in science as opposed to just my own research projects.” Two of Yeung’s research projects at Ames Laboratory have just been renewed for another 3 years, and he has a research group with ⬎20 graduate students at Hunan University (China), where two full professors and two associate professors are working for him. Yeung anticipates traveling there several times per year in addition to advising them remotely. “I think of this more like a permanent sabbatical,” says Yeung. “I’ll be busier in the things I choose to do.” Those activities will include science advisory roles in Hong Kong and elsewhere in China on the future direction and funding of the research enterprises there. In a way, his career has come full circle as he now realizes some long-held goals. “My wife and I were from big cities, and I thought we would live in a big city, and Ames was quite small. Fortunately, it was an extremely good place to work, and it’s a very nice city to start a family,” Yeung recalls. With his two children now grown, Yeung and his wife are moving to San Diego, a convenient perch from which to work on science issues in Pacific Rim countriesObut also to fulfill a longheld personal dream: “I’m finally going to the West Coast and living in a big city,” he laughs. Although he is not going far, he will be missed. Callis sums up how many people in the analytical chemistry community feel about Yeung and his work: “It has been entertaining and amusing to see that someone could be so creative and could constantly surprise and amaze usOsort of like one of the great composers, always surprising and delighting us with his new angles and insights.” Despite his retirement, Yeung will likely delight and amaze for years to come. —Deborah Illman
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among them the ACS Award in Chromatography. On that occasion, Sepaniak had arranged a symposium in Yeung’s honor, and one of the speakers was Georges A. Guiochon of the University of Tennessee. “Guiochon characterized Yeung as ‘one of those people who can reach his hands down into the muck and mire and pull out a diamond,’” says Sepaniak. “And that’s really true. You think everything is all muddled, and Ed can pull that diamond out that really advances measurement science.” Yeung and his wife, Anna, in Suzhou, China One of those diamonds would have comparing CE with single-molecule obto be the observation of varying chemical servations (Anal. Chem. 2007, 79, reactivities among individual molecules of 6047⫺6054). The paper, in effect, “harthe enzyme lactate dehydrogenase (Nature 1995, 373, 681⫺683), a finding that monizes” two areas of research: singlemolecule studies and LC. “We do both in arose from Yeung’s work on single-molour lab, and for a long time, these were ecule detection. “Analytical chemists altotally separate,” observes Yeung. “Singleways want to push detection limits, and molecule work deals with the very, very the ultimate detection limit is one molsmall, and chromatography deals with the ecule,” says Yeung. “But in the process of very large. This particular article basically being able to see single molecules, we also showed that one type of experiment can found that they have different activities.” predict the other, completely. They are Even though these large biomolecules may have the same primary structure, their one and the same.” It’s a sort of unified field theory of chromatography, he folding patternsOwhich influence their explains. activityOare unique. But when the NaThe result “brings credibility to the ture paper was published, not everyone field of chromatographyOthat it’s not got on board with the idea: “I would say only empirical [but is] based on fundathat about half of the biochemists that I mental principles,” says Yeung. “And on talked to believed the result and [exthe other hand, it shows that single-molpected] the molecules to be different, but the other half insisted that they should not ecule work is not exoticOit actually relates to work we’re doing all the time. This is be,” recalls Yeung. Since the publication very recent work, and the real impact has of that paper, many experiments in other not yet been felt, but I am hopeful that labs have confirmed the result, he says. people will now be able to use this apRecently, X-ray crystallographic work by proach to understand their own research, Yeung and colleagues confirmed that lacwhether it’s chromatography or singletate dehydrogenase exists in several differmolecule work.” ent structural forms. “So that really nails down the relationship between conformaContinuing to shape the field tion and activity,” Yeung says. He adds Yeung is now entering a new period of his that the work has implications for drug career, one that can hardly be called retiredesign, because multiple drugs might be ment. Although he officially retired in Auneeded to target an enzyme with many gust, he is “already fully booked until Febconformations. ruary in terms of travel, talks, panels, and Another great achievement of Yeung’s so forth,” he admits. “I think it’s more a is his paper on adsorption isotherms for matter of refocusing my energy to the part
