Technology Forum: Capillary Electrophoresis

A mature technique that is finding new and innovative applications every day, capillary electrophoresis has come to the forefront in much of the recent literature, with the feature article of the August issue of LCGC being dedicated to this technique. We expect that interest in CE will only continue to grow in the future.

This month, Chromatography Online's Technology Forum looks at the topic of capillary electrophoresis and the trends and issues surrounding it. Joining us for this discussion are Tobias Preckel of Agilent Technologies; Susan Darling of Beckman Coulter, Inc.; and Frank A. Gomez of California State University.

What new developments in capillary electrophoresis have you most intrigued?

Preckel: CE has been a viable orthogonal technology to liquid chromatography in the Pharma and Chemical markets. It excels in the area of separation for ions, chiral, polar, and biological compounds (DNA, RNA, proteins) where LC often lacks separation power. Most excitingly, coupling CE to high-end mass spectrometry is an emerging and intriguing application. Another nascent and intriguing application field for CE is label-free fluorescence detection of proteins.

Darling:Over the last few years CE has transitioned from an analytical, research tool to broader application use in the routine analysis and quality control of biotherapeutic drugs, particularly monoclonal antibodies. The maturity of CE as a technique has allowed the incorporation of CE into a routine use environment such that universities are now incorporating CE into their programs and moving away from SDS-PAGE and IEF gel based methods. Another intriguing development is in CE-MS. New high sensitivity and more robust CE-MS interface designs have allowed broader application of this technology for biomarker discovery, monitoring of disease state, and characterization of pharmaceuticals, including intact protein therapeutics. Short analysis times combined with dynamic mass exclusion provide high sequence coverage with CE-MS and positions this technology to provide significant contributions to pre- clinical and clinical applications.

Gomez: I am biased and have a particular interest in microchip CE (MCE). Really, almost anything that can be studied in open tubular capillaries should be able to be studied on a chip and for less money. This miniaturization process is on-going and is already being seen in the private sector. I envision new start-up companies filling niches where the big commercial CE companies once ruled. These start-ups, though, must demonstrate the versatility of CE by providing a myriad of applications that are robust, inexpensive, reliable, and reproducible.

Do you expect any major developments/news about capillary electrophoresis to be presented at Pittcon 2009?

Preckel: We are expecting new kits supporting applications in the analysis of biopharmaceuticals and chiral compounds.

Darling:CE has shown strength in the pharmaceutical industry and we anticipate new developments from the industry in both instrumentation and applications with a focus on operational efficiency and application-specific solutions.

Gomez:There are some interesting presentations on detection techniques in MCE, chiral CE separations on chips, and nanoparticles in CE that I will be attending not to mention the biological applications of CE symposium I was invited to present at.

What is the capillary electrophoresis application that you see growing the fastest?

Preckel: We are clearly seeing an increasing demand for CE applications in the area of biopharmaceutical drugs. In addition, chemical applications such as ion analysis, forensics, and impurity detection for pharmaceuticals have experienced veritable growth.

Darling:The biopharmaceutical industry has adopted CE-SDS and cIEF as fundamental tools for characterization and analysis of their protein products. These applications are growing very quickly as CE demonstrates it is capable of high resolution and robust separations. Oligosaccharide analysis is also growing quickly. We are now seeing adoption of these techniques with all areas of the biopharmaceutical industry and also earlier in the drug development process. Companies are now utilizing CE for more rigorous analysis of clone selection and product purification processes as the speed and resolution of CE can provide greater efficiency.

Gomez:I feel the development of MCE will continue to be a major focus of many research labs and the private sector. Lab miniaturization and high-throughput screening are driving the development, especially as it pertains to proteomic and genomic problems.

What obstacles stand in the way of capillary electrophoresis development?

Preckel: CE offers the advantage of flexibility and method development options. It accommodates several separation modes, detectors, and can be applied to a broad range of large and small compounds. This flexibility can be seen as intimidating. In recent years, however, standardization and publicly available methods and knowledge base have paved the way to a broader acceptance.

Darling:Next year CE will celebrate 20 years as a commercially available technology. Over this period CE has gained acceptance as a robust, high-resolution methodology in biopharma, however adoption of this technique has been slow across all industries. Existing techniques and methodologies can be difficult to displace due to regulatory concerns and lack of familiarity with CE. Additionally the lack of experienced capillary electrophoresis operators has also impeded mainstream CE implementation. Universities are just now starting to incorporate capillary electrophoresis into their laboratory curriculum and will surely help address some of these concerns.

Gomez:To an extent, CE is still a niche technique. There was once the belief that it would take the place of HPLC but I feel this statement was premature. I feel the market for growth in CE instruments is there, but more robust applications need to be developed to grow this market. As for specific scientific obstacles, the limitations imposed by the path length of capillary columns will always be a concern when low limits of detection (LOD) are important. Hence, it is critical that new commercial CE instrumentation provide as many detector options as possible.

What is the future of capillary electrophoresis?

Preckel: CE is beyond a stage where the technology is expected to prove its validity. Taking Pharma’s shifting focus on large biological molecules and the increasing FDA requirements for orthogonal separation techniques into account, CE has a bright future ahead as an analytical tool.

Darling:We see capillary electrophoresis becoming a mainstream analytical tool with advances in current technology making for easier and more robust applications not only in biopharma, but also in areas such as forensics, food and beverage, biofuels, agribusiness, and other industrial segments.

Industry requirements for reducing product development cycles and increased sensitivity will require advances in all aspects of sample handling and analysis and will be facilitated by innovations in hardware, software, and applications. High-resolution generic method platforms will be integral in reducing method development and providing higher efficiency.

Gomez:I see a bright future for CE but only if the technology and its respective applications are marketed broadly in many scientific disciplines. Certainly, the cost of reagents needed in a typical CE application and speed of analysis are major advantages over other analytical technique. It is good aspects like this that will be a major reason for the future of CE.