The AES Electrophoresis Society—formerly the American Electrophoresis Society—has over four decades of history that began, in the 1970s, with meetings of biochemists, chemists, and chemical engineers to discuss new advances in the electrophoretic separation technologies of the day. Over repeated meetings, the idea to found a society was born, and the AES has gone from strength to strength. Since 2000, the annual meeting has been held in conjunction with the American Institute of Chemical Engineers' annual meeting, but attracts a broad spectrum of academics and industry from medicine and the life sciences through to electronic and mechanical engineers, bioengineers and physicists, as well as chemical engineers and biochemists. The 2015 meeting was held in the beautiful location of Salt Lake City, and as befits a town named after a large body of dissolved ions, the group “charged” to the city to deliver their latest results. This Special Issue represents a cross-section of papers selected from those presenting. Examining the breadth of these papers, it is interesting to note that the most common sub-discipline to appear, forming a plurality if not a majority, is a subject which would almost certainly have received scant, if any, discussion in the original meetings in the 1970s. Dielectrophoresis (DEP) is a close relative of electrophoresis, but one where the action of electric field upon a dipole (permanent or, much more commonly, induced) allows the use of both AC and DC fields to manipulate cells and other suspended particles. Indeed, this year—2016—marks the 50th anniversary of the first paper to be published showing that not only could living and dead cells be manipulated, but that they could be separated based on differences in their response to an applied field of similar frequency. The five papers on dielectrophoresis presented here cover a broad range, with many focussing on new approaches to electrode design and manufacture, through to increasing the throughput and selectivity of the separations. Examples include electrodes manufactured from platinum black threads1 to carbonized SU8,2 novel geometries such as the nanoslit,3 and new applications such as the detection of Babeosis in blood cells.4 Finally, Mata-Gomez and colleagues5 report on a DEP-based device for capturing macromolecules. Interestingly, many of these papers use yeast as a model organism—just as in the 1966 paper. Advances across the other sub-disciplines of Electrophoresis are all represented; Saucedo-Espinosa and Lapizco-Encinas advance the understanding of electro-osmotic flow in low ionic strength media;6 capillary electrophoresis is represented by Paracha and Hestekin who use the technique to increase beta amyloid aggregation;7 whilst the colleagues of Victor Ugaz describe two processes with implication for microfabrication, one additive and one subtractive; Shi and Ugaz8 describe electro-polymerization of hydrogels constructed using microelectrodes, whilst Huang et al.9 describe a highly novel enzyme-based fabrication process for micromachining of channels. This year's AES Electrophoresis Society Annual Meeting also included several entries to the “Art in Microfluidic Science” competition that was jointly sponsored by the AES Electrophoresis Society and AIP's Biomicrofluidics journal. Among the winning entries on the video include Tayloria Adams, a postdoc at UC, Irvine showing dielectrophoretic patterning of sickle cells (Best Video—https://www.youtube.com/watch?v=UFJGmHnHtU0), Renny E. Fernandez of Southern Methodist University showing dielectrophoretic profiles of cells created by mesoscopic threads coated with Pt black1 (Runner up Video—https://www.youtube.com/watch?v=XwoJg3YV0pU&feature=youtu.be) and Aashish Priye, a scientist at Sandia profiling advances in convective PCR (Honorable Mention—https://www.youtube.com/watch?v=-zWgg7yo1ak&feature=youtu.be). The best image entitled: “Miscarried Separation in a Spider Channel Microdevice” was presented by Mario Saucedo of Rochester Institute of Technology. The runner-up image award entitled: “A Bacteria Flower,” was presented by Avanish Mishra, a student at Purdue University. The image winning an honourable mention entitled: “Conductivity gradient-enhanced dielectrophoresis”3 was presented by Ali Rohani, a graduate student at University of Virginia (see Supplementary Material, Ref. 13, for images). Finally, we are thrilled to present two significant reviews of their fields: one by Egatz-Gomez et al.10 on porous materials in microfluidics, and the other on microfluidic approaches to nucleic acid detection in liquid biopsy by Knob et al.11 And to coincide with the 50th anniversary of the publication of the first paper on dielectrophoretic separation, there is a Perspective article on the path that dielectrophoretic cell separation has taken in the last 50 years,12 including the recollections of the student—now a retired professor—who performed the first experiments that started a discipline. In his comments he reflected that “I had no idea the paper by Pohl and I would have much of an impact”; who knows where the papers here, or the future of Electrophoresis, may take us?
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Sep 13, 2024
Lucia Billeci + 6
Open Access