Separation technology unites lab, new company

Breakthroughs from the labs of Ed Yeung are no surprise. Yeung, Chemical and Biological Sciences program director and a distinguished professor chemistry at Iowa State University, has a long history of innovations in analytical chemistry.

But one of Yeung's latest developments — multiplexed capillary electrophoresis using absorption detection — stands out in many ways. One is the technology's potential to be widely used. "Any kind of chemical measurements that involve separation can, in principle, be fitted to use this technology," Yeung says. The technology works on a large variety of compounds and can be used by pharmaceutical, genetics, medical and forensics labora-tories, and someday, even doctors' offices.

This innovation also marks the first time Yeung has been directly involved in launching a new company based on his technology. Yeung helped found CombiSep Inc. instead of licensing the technology to another company in an effort to accelerate the development process. "I realized we needed to move extremely fast," he says. "We had to do something right here, and quickly."

Indeed, "fast" seems to be CombiSep's catchword. From the company's technology and product-development process to its potential markets, speed is of the essence for CombiSep. It all starts with the advantages of multiplexed capillary electrophoresis: the technology can evaluate compounds faster and less expensively than alternatives.

What's more, the applications that the company is aiming at — including combinatorial chemistry, drug discovery, genomics and proteomics (the study of protein expression and function) — are fast evolving. "You have to be out there first and get a foothold in different applications," Yeung says.

The market for high-throughput analysis technologies such as muliplexed capillary electrophoresis is "hot" right now, according to Shelley Coldiron, CombiSep president and a former associate of the Institute for Physical Research and Technology. CombiSep is striving to get into this market as quickly as possible, especially as it is competing with several large companies in the fast-growing, multibillion dollar market for these instruments. "There's always someone out there developing similar ideas," Coldiron says.

But perhaps the fastest aspect of CombiSep is the speed at which the company is developing its technology. Yeung began his Ames Lab research on the technology in 1998. CombiSep, although officially founded in December 1999, really didn't get rolling until April 2000. Since then, the company has made and tested several prototypes of its MCE 2000 multiplex capillary electrophoresis instrument. CombiSep is shipping its first machine to Procter & Gamble Pharmaceuticals for evaluation in late February. In the short time, the company also raised $1 million in start-up funds.

CombiSep has been able to move quickly for several reasons, according to Coldiron. First, Yeung had already proved that the technology would work. Second, CombiSep has been able to hire top-notch technologists, including co-inventor Ho-Ming Pang, a former IPRT scientist, and Roy Strasburg and Jeremy Kenseth, both Ph.D. chemistry graduates from ISU. Third, the company has contracted resources and expertise from various ISU organizations, including Ames Lab and IPRT as well as ISU's Center for Research and Industrial Service. "Working with the university has been valuable to us," Coldiron says.

CIRAS is serving as a "surrogate engineering department" for CombiSep, according to Don Eichner, senior staff engineer at CIRAS. Eichner and his team are helping design and build the initial prototypes of the MCE 2000. CIRAS, in turn, contracts with Ames Lab's Engineering Services Group to fabricate various components and to design and build the electronics that go into the machine.

Jerry Hand, supervisor of the Lab's mechanical development shop, says the CombiSep project is "pretty much" like the others his group works on. Much of the effort consists of fabricating components made of aluminum and other materials using the shop's lathes, mills and wire electrical discharge machining system. Hand says his entire group, including Steve Lee, Charles Burg, Jim Berninghaus and Bill Wing, has worked on the CombiSep project. In addition, the Lab's electronics tech shop helped design the electronics for the prototype. John Hjortshoj, the shop's supervisor, worked on this project, along with Lee Harker and Jerry Musselman.

IPRT's Center for Advanced Technology Development is also assisting CombiSep. Helping move a concept from research and development to product development is CATD's forte; still, Carey Novak, a technology transfer associate at CATD, says CombiSep's story is notable. "We're excited about the company because we have everything we need contained within this campus," he says.

In addition to Yeung and Coldiron, the company's founders include Marc Porter, an ISU chemistry professor and director of IPRT's Microanalytical Instrumentation Center, serving as vice-president; Steve Ringlee, a well-known Ames entrepreneur and founder of several high-tech companies, serving as COO and treasurer; and Strasburg, director of R&D. CombiSep is currently leasing space at the Applied Sciences Complex.

Although Coldiron admits that starting a new company in Iowa has its challenges, CombiSep has been able to garner the majority of its start-up funds from local investors. Coldiron said experience is essential when it comes to getting a company up and running. "The best thing you can do is find someone who has gone through it before," she says.

CombiSep's goal, says Coldiron, is to not just be an instrument-maker but a supplier of solutions to its customers. Toward that end, the company has plans to offer a system for sample preparation as well.

Perhaps the best way to grasp how the MCE 2000 works is by understanding its component technologies. Capillary electrophoresis works on the same principles as gel electrophoresis, commonly used in DNA fingerprinting: an electrical current causes molecules to migrate at different speeds, according to size and charge. The capillaries are silica tubes about 2 feet long, with an inside diameter of 75 microns (about the diameter of a human hair). Because capillaries can disperse heat so well, an electrical charge of up to 20,000 volts can be used. The high voltage means fast separations; CombiSep's machine can perform separations in as little as 15 minutes.

"Absorbance detection" describes how the system detects molecules. Ultraviolet light is focused through a tiny window to illuminate the capillaries, and the amount of light absorbed by the migrating molecules is detected by an array of photodiodes. This data, along with the time it takes the molecules to migrate, is sent to a standard personal computer. Custom software processes the data, revealing the type and quantity of the separated compounds.

"Multiplex" means that the machine runs several analyses at a time by using multiple capillaries — 96 in the case of the standard MCE 2000. The machine is made to work with standard 96-well titer plates and can handle up to 10 of them on a rotating platter. The end result is automated, high-throughput analysis, a much-sought-after technology in today's biotech industries.

Multiplexed capillary electrophoresis with absorption detection competes against other separation technologies, including high-performance liquid chromatography and capillary electrophoresis with fluorescence detection.

"HPLC is a widely accepted practice," says Coldiron, and that makes it more difficult to compete against. "We have to educate people and let them know we can operate comparable to what they're getting with HPLC." Toward that end, CombiSep's scientists are making the rounds at conferences and trade shows to explain the advantages of the company's technology.

Another factor working in CombiSep's favor is that its technology uses less solvent than HPLC. "We use 1,000 times less solvent than HPLC," says Coldiron, noting that this results in lower environmental hazards and related costs. And, while an HPLC system costs much less than CombiSep's machine, Coldiron says, "We can take 96 of those individual instruments and do the analyses with one of ours."

Capillary electrophoresis systems that use laser-excited, fluorescence detection are also made in multiplexed versions that can run 96 analyses at a time. These type of machines play a key role in DNA sequencing; in fact, Yeung won an R&D 100 Award for developing just such an instrument in the 1990s.

Yeung's latest technology, however, can handle a wider variety of compounds, thanks to its ability to detect molecules through ultraviolet detection. "Only about 10 percent of all compounds fluoresce naturally," says Coldiron, "so you have to put an optical tag on those compounds that don't fluoresce naturally." The "optical tags" are fluorescent dyes that are expensive and may be toxic.

What's more, multiplexed systems can be slow at processing all the data that results from running 96 simultaneous analyses. "It's kind of self-defeating. You're generating all this data but you get bottlenecked in data processing," Coldiron says. To sidestep this hurdle, Pang has written software that can process the data in 30 minutes, according to Coldiron.

by Bob Mills