{"527451":{"#nid":"527451","#data":{"type":"news","title":"Cellphone Principles Help Microfluidic Chip Digitize Information on Living Cells","body":[{"value":"\u003Cp\u003EPhone calls and text messages reach you wherever you are because your phone has a unique identifying number that sets you apart from everybody else on the network. Researchers at the Georgia Institute of Technology are using a similar principle to track cells being sorted on microfluidic chips.\u003C\/p\u003E\u003Cp\u003EThe technique uses a simple circuit pattern with just three electrodes to assign a unique seven-bit digital identification number to each cell passing through the channels on the microfluidic chip. The new technique also captures information about the sizes of the cells, and how fast they are moving. That identification and information could allow automated counting and analysis of the cells being sorted.\u003C\/p\u003E\u003Cp\u003EThe research, reported in the journal \u003Cem\u003ELab on a Chip\u003C\/em\u003E, could provide the electronic intelligence that might one day allow inexpensive labs on a chip to conduct sophisticated medical testing outside the confines of hospitals and clinics. The technology can track cells with better than 90 percent accuracy in a four-channel chip.\u003C\/p\u003E\u003Cp\u003E\u201cWe are digitizing information about the sorting done on a microfluidic chip,\u201d explained Fatih Sarioglu, an assistant professor in Georgia Tech\u2019s School of Electrical and Computer Engineering. \u201cBy combining microfluidics, electronics and telecommunications principles, we believe this will help address a significant challenge on the output side of lab-on-a-chip technology.\u201d\u003C\/p\u003E\u003Cp\u003EMicrofluidic chips use the unique biophysical or biochemical properties of cells and viruses to separate them. For instance, antigens can be used to select bacteria or cancer cells and route them into separate channels. But to obtain information about the results of the sorting, those cells must now be counted using optical methods.\u003C\/p\u003E\u003Cp\u003EThe new technique, dubbed microfluidic CODES, adds a grid of micron-scale electrical circuitry beneath the microfluidic chip. Current flowing through the circuitry creates an electrical field in the microfluidic channels above the grid. When a cell passes through one of the microfluidic channels, it creates an impedance change in the circuitry that signals the cell\u2019s passage and provides information about the cell\u2019s location, size and the speed at which it is moving through the channel.\u003C\/p\u003E\u003Cp\u003EThis impedance change has been used for many years to detect the presence of cells in a fluid, and is the basis for the Coulter Counter which allowed blood counts to be done quickly and reliably. But the microfluidic CODES technique goes beyond counting.\u003C\/p\u003E\u003Cp\u003EThe positive and negative charges from the intermingled electrical circuits create a unique identifying digital signal as each cell passes by, and that sequence of ones and zeroes is attached to information about the impedance change. The unique identifying signals from multiple cells can be separated and read by a computer, allowing scientists to track not only the properties of the cells, but also how many cells have passed through each channel.\u003C\/p\u003E\u003Cp\u003E\u201cBy judiciously aligning the grid pattern, we can generate the codes at the locations we choose when the cells pass by,\u201d Sarioglu explained. \u201cBy measuring the current conduction in the whole system, we can identify when a cell passes by each location.\u201d\u003C\/p\u003E\u003Cp\u003EBecause the cells sorted into each channel of a microfluidic chip have certain characteristics in common, the technique would allow the automated detection of cancer cells, bacteria or even viruses in a fluid sample. Sarioglu and his students have demonstrated that they can track more than a thousand ovarian cancer cells with an accuracy rate of better than 90 percent.\u003C\/p\u003E\u003Cp\u003EThe underlying principle for the cell identification is called code division multiple access (CDMA), and it\u2019s essential for helping cellular networks separate the signals from each user. The microfluidic channels are fabricated from a plastic material using soft lithographic techniques. The electrical pattern is fabricated separately on a glass substrate, then aligned with the plastic chip\u003C\/p\u003E\u003Cp\u003E\u201cWe have created an electronic sensor without any active components,\u201d Sarioglu said. \u201cIt\u2019s just a layer of metal, cleverly patterned. The cells and the metallic layer work together to generate digital signals in the same way that cellular telephone networks keep track of each caller\u2019s identity. We are creating the equivalent of a cellphone network on a microfluidic chip.\u201d\u003C\/p\u003E\u003Cp\u003EThe next step in the research will be to combine the electronic sensor with a microfluidic chip able to actively sort cells. Beyond cancer cells, bacteria and viruses, such a system could also sort and analyze inorganic particles.\u003C\/p\u003E\u003Cp\u003EThe computing requirements of the system would be minimal, requiring no more than the processor power of smartphones that already handle decoding of CDMA signals. The proof-of-principle device contains just four channels, but Sarioglu believes the design could easily be scaled up to include many more channels.\u003C\/p\u003E\u003Cp\u003E\u201cThis is like putting a USB port on a microfluidic chip,\u201d he explained. \u201cOur technique could turn all of the microfluidic manipulations that are happening on the chip into quantitative data related to diagnostic measurements.\u003C\/p\u003E\u003Cp\u003EUltimately, the researchers hope to create inexpensive chips that could be used for sophisticated diagnostic testing in physician offices or remote locations. Chips might be contained on cartridges that would automate the testing process.\u003C\/p\u003E\u003Cp\u003E\u201cIt will be very exciting to scale this up, and I think that will open up the possibility for many different assays to become accessible electronically,\u201d Sarioglu said. \u201cDecentralizing health care is an important trend, and our technology might one day allow many kinds of diagnostic tests to be done beyond hospitals and large medical facilities.\u201d\u003C\/p\u003E\u003Cp\u003EOther co-authors of the paper included Ruxiu Liu, Ningquan Wang, and Farhan Kamili, all Georgia Tech graduate students.\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ECITATION\u003C\/strong\u003E: Ruxiu Liu, Ningquan Wang, Farhan Kamili and A. Fatih Sarioglu, \u201cMicrofluidic CODES: a scalable multiplexed electronic sensor for orthogonal detection of particles in microfluidic channels,\u201d (Lab on a Chip, 2016). \u003Ca href=\u0022http:\/\/dx.doi.org\/10.1039\/c6lc00209a\u0022\u003Ehttp:\/\/dx.doi.org\/10.1039\/c6lc00209a\u003C\/a\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EResearch News\u003C\/strong\u003E\u003Cbr \/\u003E\u003Cstrong\u003EGeorgia Institute of Technology\u003C\/strong\u003E\u003Cbr \/\u003E\u003Cstrong\u003E177 North Avenue\u003C\/strong\u003E\u003Cbr \/\u003E\u003Cstrong\u003EAtlanta, Georgia 30332-0181 USA\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EMedia Relations Contacts\u003C\/strong\u003E: John Toon (\u003Ca href=\u0022mailto:jtoon@gatech.edu\u0022\u003Ejtoon@gatech.edu\u003C\/a\u003E) (404-894-6986) or Ben Brumfield (\u003Ca href=\u0022mailto:ben.brumfield@comm.gatech.edu\u0022\u003Eben.brumfield@comm.gatech.edu\u003C\/a\u003E) (404-385-1933).\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EWriter\u003C\/strong\u003E: John Toon\u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003EPhone calls and text messages reach you wherever you are because your phone has a unique identifying number that sets you apart from everybody else on the network. Researchers at the Georgia Institute of Technology are using a similar principle to track cells being sorted on microfluidic chips.\u0026nbsp;\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"Researchers are borrowing cellphone technology to track living cells on microfluidic chips."}],"uid":"27303","created_gmt":"2016-04-20 17:30:20","changed_gmt":"2016-10-08 03:21:25","author":"John Toon","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2016-04-20T00:00:00-04:00","iso_date":"2016-04-20T00:00:00-04:00","tz":"America\/New_York"},"extras":[],"hg_media":{"527371":{"id":"527371","type":"image","title":"Hybrid chip uses cellphone principles","body":null,"created":"1461337200","gmt_created":"2016-04-22 15:00:00","changed":"1475895301","gmt_changed":"2016-10-08 02:55:01","alt":"Hybrid chip uses cellphone principles","file":{"fid":"205561","name":"hybrid-chip_3168.jpg","image_path":"\/sites\/default\/files\/images\/hybrid-chip_3168_1.jpg","image_full_path":"http:\/\/hg.gatech.edu\/\/sites\/default\/files\/images\/hybrid-chip_3168_1.jpg","mime":"image\/jpeg","size":293754,"path_740":"http:\/\/hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/hybrid-chip_3168_1.jpg?itok=clyxT3xX"}},"527391":{"id":"527391","type":"image","title":"Closeup of hybrid chip","body":null,"created":"1461337200","gmt_created":"2016-04-22 15:00:00","changed":"1475895301","gmt_changed":"2016-10-08 02:55:01","alt":"Closeup of hybrid chip","file":{"fid":"205563","name":"hybrid-chip-004.jpg","image_path":"\/sites\/default\/files\/images\/hybrid-chip-004_1.jpg","image_full_path":"http:\/\/hg.gatech.edu\/\/sites\/default\/files\/images\/hybrid-chip-004_1.jpg","mime":"image\/jpeg","size":685041,"path_740":"http:\/\/hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/hybrid-chip-004_1.jpg?itok=gQ3tLPTH"}},"527411":{"id":"527411","type":"image","title":"Ovarian cancer cells in microfluidic chip","body":null,"created":"1461337200","gmt_created":"2016-04-22 15:00:00","changed":"1475895301","gmt_changed":"2016-10-08 02:55:01","alt":"Ovarian cancer cells in microfluidic chip","file":{"fid":"205559","name":"hybrid-chip_3165.jpg","image_path":"\/sites\/default\/files\/images\/hybrid-chip_3165_1.jpg","image_full_path":"http:\/\/hg.gatech.edu\/\/sites\/default\/files\/images\/hybrid-chip_3165_1.jpg","mime":"image\/jpeg","size":329536,"path_740":"http:\/\/hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/hybrid-chip_3165_1.jpg?itok=bgisaQCD"}},"527431":{"id":"527431","type":"image","title":"Developing hybrid chips","body":null,"created":"1461337200","gmt_created":"2016-04-22 15:00:00","changed":"1475895301","gmt_changed":"2016-10-08 02:55:01","alt":"Developing hybrid chips","file":{"fid":"205607","name":"hybrid-chip-007.jpg","image_path":"\/sites\/default\/files\/images\/hybrid-chip-007_0.jpg","image_full_path":"http:\/\/hg.gatech.edu\/\/sites\/default\/files\/images\/hybrid-chip-007_0.jpg","mime":"image\/jpeg","size":1248337,"path_740":"http:\/\/hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/hybrid-chip-007_0.jpg?itok=KDMnw31Y"}}},"media_ids":["527371","527391","527411","527431"],"groups":[{"id":"1188","name":"Research Horizons"}],"categories":[{"id":"140","name":"Cancer Research"},{"id":"146","name":"Life Sciences and Biology"},{"id":"135","name":"Research"}],"keywords":[{"id":"385","name":"cancer"},{"id":"171942","name":"CDMA"},{"id":"532","name":"cell"},{"id":"170155","name":"cellphone"},{"id":"171943","name":"Fatih Sarioglu"},{"id":"170154","name":"lab on a chip"},{"id":"12427","name":"microfluidics"}],"core_research_areas":[{"id":"39441","name":"Bioengineering and Bioscience"},{"id":"39451","name":"Electronics and Nanotechnology"},{"id":"39501","name":"People and Technology"}],"news_room_topics":[{"id":"71891","name":"Health and Medicine"}],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003EJohn Toon\u003C\/p\u003E\u003Cp\u003EResearch News\u003C\/p\u003E\u003Cp\u003E\u003Ca href=\u0022mailto:jtoon@gatech.edu\u0022\u003Ejtoon@gatech.edu\u003C\/a\u003E\u003C\/p\u003E\u003Cp\u003E(404) 894-6986\u003C\/p\u003E","format":"limited_html"}],"email":["jtoon@gatech.edu"],"slides":[],"orientation":[],"userdata":""}}}