Microfabricated Centrifugal Microfluidic Systems: Characterization and Multiple Enzymatic Assays
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- 作者：David C. Duffy ; Heather L. Gillis ; Joe Lin ; Norman F. Sheppard ; Jr. ; and Gregory J. Kellogg
- 刊名：Analytical Chemistry
- 出版年：1999
- 出版时间：October 15, 1999
- 年：1999
- 卷：71
- 期：20
- 页码：4669 - 4678
- 全文大小：209K
- 年卷期：v.71,no.20(October 15, 1999)
- ISSN：1520-6882
文摘
This paper describes a microfluidic system in which fluidsare pumped by centrifugal force through microscopicchannels defined in a plastic disk in order to performcomplex analytical processes. The channels are createdeither by casting poly(dimethylsiloxane) against moldsfabricated by photolithography or by conventional machining of poly(methyl methyacrylate). The channels havea wide range of diameters (5 
m-0.5 mm) and depths(16 m-3 mm). Fluids are loaded into reservoirs nearthe center of the disk, the disk is rotated on the shaft ofa simple motor at 60-3000 rpm, and the fluids arepumped outward by centrifugal force through microfluidicnetworks. The control of flow in the time domain, i.e.,gating, is achieved by the use of passive valves based oncapillary forces. Flow rates ranging from 5 nL/s to >0.1mL/s have been achieved using channels of differentdimensions and different rates of rotation. The methodof pumping is insensitive to many physicochemical properties of the liquid, such as pH and ionic strength, so ithas been possible to pump biological fluids, such as bloodand urine, a buffer containing a detergent, and someorganic solvents. A system that performs multiple (48)enzymatic assays simultaneously using colorimetric detection on a dedicated instrument has been demonstrated.These integrated assays have been used both to yield theMichaelis constant (Km) of an enzyme and to determinethe dose response of an enzyme to a drug. The fluidpumping and control embodied in this system may bereadily integrated with other analytical components (e.g.,heating, detection, and informatics) to form the basis fora microscale total analysis system for use in genomics,proteomics, high-throughput screening, and moleculardiagnostics.
m-0.5 mm) and depths(16 m-3 mm). Fluids are loaded into reservoirs nearthe center of the disk, the disk is rotated on the shaft ofa simple motor at 60-3000 rpm, and the fluids arepumped outward by centrifugal force through microfluidicnetworks. The control of flow in the time domain, i.e.,gating, is achieved by the use of passive valves based oncapillary forces. Flow rates ranging from 5 nL/s to >0.1mL/s have been achieved using channels of differentdimensions and different rates of rotation. The methodof pumping is insensitive to many physicochemical properties of the liquid, such as pH and ionic strength, so ithas been possible to pump biological fluids, such as bloodand urine, a buffer containing a detergent, and someorganic solvents. A system that performs multiple (48)enzymatic assays simultaneously using colorimetric detection on a dedicated instrument has been demonstrated.These integrated assays have been used both to yield theMichaelis constant (Km) of an enzyme and to determinethe dose response of an enzyme to a drug. The fluidpumping and control embodied in this system may bereadily integrated with other analytical components (e.g.,heating, detection, and informatics) to form the basis fora microscale total analysis system for use in genomics,proteomics, high-throughput screening, and moleculardiagnostics.