AUTHORS: V.J. Sieben1, C. Debes-Marun2, P.M. Pilarski1, G.K. Kaigala1, L.M. Pilarski2 and C.J. Backhouse1
1 Department of Electrical & Computer Engineering, University of Alberta, Edmonton, Canada, and 2 Cross Cancer Institute, Edmonton, Canada
Introduction: Interphase fluorescence in situ hybridization (FISH) is a sensitive diagnostic tool used for the detection of chromosomal abnormalities on cell-by-cell basis, that can predict prognosis and response to therapy. However, the cost-per-test and the technical complexity of current FISH protocols has compromised its widespread utilization. Lab-on-a-chip devices miniaturize, integrate and automate conventional analytical techniques onto microfluidic platforms. Since microchannels permit sophisticated levels of fluid control, these devices can reduce analysis times, lower reagent consumption, and minimize human intervention. Materials and methods: We present both glass and PDMS microfluidic platforms that standardize much of the FISH protocol offering repeatable results that are accurate, cost-effective and easy to obtain in a clinical setting. Furthermore, we examine on-chip methods to enhance the hybridization portion of FISH; specifically, mechanical or electrokinetic pumping. To verify the robustness of our microchip FISH protocols, multiple probe and cell combinations were tested. Results: Compared to conventional methods, these first implementations of on-chip FISH provide a 10-fold higher throughput and a 10-fold reduction in the cost of testing, enabling the simultaneous assessment of several chromosomal abnormalities or patients. In addition, the two methods of on-chip agitation improve the hybridization rate and are currently being optimized. We also demonstrate that the time limiting mechanisms during hybridization can be minimized even further using microchip methods. Conclusions: It is increasingly essential that diagnostic tests determine the type and extent of chromosomal abnormalities for more informed diagnosis and for appropriate choice of treatment strategies. On-chip FISH technology allows chromosomal analysis in hours as opposed to days. Further, the on-chip FISH technique introduced here was 10 times more cost-effective than conventional methods with the potential to be fully integrated and automated. This technology will make wide-spread genetic testing of myeloma patients more accessible in a clinical setting. This work was supported by the Natural Sciences and Engineering Research Council (NSERC), the Informatics Circle of Research Excellence (iCORE), the Alberta Ingenuity Fund, a Western Economic Diversification grant, and the Canadian Institutes of Health Research (CIHR).