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Accelerated Article

Microfluidic Devices for the High-Throughput Chemical Analysis of Cells

Supporting Info

Maxine A. McClain,^† Christopher T. Culbertson,^‡ Stephen C. Jacobson, Nancy L. Allbritton,^§ Christopher E. Sims,^§ and J. Michael Ramsey*

Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831-6142

Anal. Chem., 2003, 75 (21), pp 5646–5655

DOI: 10.1021/ac0346510

Publication Date (Web): September 23, 2003

†

Present address: Department of Electrical and Computer Engineering, The Georgia Institute of Technology, Atlanta, GA 30332.

‡

Present address: 111 Willard Hall, Department of Chemistry, Kansas State University, Manhattan, KS 66506.

Permanent address: Department of Physiology and Biophysics, University of California, Irvine, CA 92697.

Permanent address: Center for Biomedical Engineering, University of California, Irvine, CA 92697.

To whom correspondence should be addressed: (phone) 865-574-4662; (fax) 865-574-8363; e-mail: ramseyjm@ornl.gov.

Abstract

A microfluidic device is reported that integrated cell handling, rapid cell lysis, and electrophoretic separation and detection of fluorescent cytosolic dyes. The device function was demonstrated using Jurkat cells that were loaded with the fluorogenic dyes − carboxyfluorescein diacetate, Oregon green carboxylic acid diacetate, or Calcein AM. The loaded cells were hydrodynamically transported from the cell-containing reservoir to a region on the microfluidic device where they were focused and then rapidly lysed using an electric field. Complete lysis was accomplished in <33 ms. The hydrolyzed, fluorescent dyes in the cell lysate were automatically injected into a separation channel on the device and detected 3 mm downstream of the injection point. The total separation time was 2.2 s with absolute migration time reproducibilities of <1% and efficiencies ranging from 2300 to 4000 theoretical plates. Results from 139 cells are reported. A small fraction of these cells, 9%, were found to enzymatically hydrolyze the loaded dyes in a manner significantly different from the majority of the cells. Cell analysis rates of 7−12 cells/min were demonstrated and are >100 times faster than those reported using standard bench-scale capillary electrophoresis.