Glass-based microchips, microchip capillary electrophoresis

An assay for uric acid in urine employing a PDMS and/or glass microchip for capillary electrophoresis has also been developed. This device can achieve separation and quantitation of uric acid in less than 30 seconds and a linear response over a range of 0 to lOOpM/L. To facilitate this measurement, dilutions of urine of the order of fiftyfold to seventy-fivefold were required. Other similar devices for the renal markers creatine, creatinine, p-aminohippuric acid, and uric acid in urine,and a microchip-based method for zone electrophoretic analysis of oxalate m urine have been reported. 

M.J. Schoning, M. Jacobs, A. Muck, D.-T. Knobbe, J. Wang, M. Chatrathi and S. Spillmann, Amperometric PDMS/glass capillary electrophoresis-based biosensor microchip for catechol and dopamine detection, Sens. Actuator B, 108 (2005) 688-694. 

Zhou et al. [175] described the determination of severe acute respiratory syndrome (SARS) coronavirus by a microfluidic chip system. The unit included an LIF microfluidic chip analyzer, a glass microchip for both PCR and capillary electrophoresis, a chip thermal cycler based on dual Peltier thermoelectric elements, a reverse transcription-polymerase chain reaction (RT-PCR) SARS diagnostic kit, and a DNA electrophoretic sizing kit. According to the authors, the system allowed efficient DNA amplification of the SARS coronavirus followed by electrophoretic sizing and detection on the same chip. 

Figure 10-4 Design of an asymmetric turn used in microchip-based capillary electrophoresis system constructed in glass.The design facilitates the maintenance of sample integrity during flow in a microchannel around a curve.The dimensions are indicated on the figure and are taken from the tops of the channels.The channels were filled with black ink for contrast (From Ramsey JD, Jacobson SC, Culbertson CT, Ramsey JM. High efficiency, two-dimensional separations of protein digests on micro fluidic devices.

Due to its simple optical devices, wide linear range of response and many well characterized CL systems, chemiluminescence (CL) is uniquely suited to on-line detection for /t-TAS. Some reports have shown that CL is an alternative promising detection method for capillary electrophoresis microchip. In the present work, some glass microchips were designed based on the flow injection and electroosmotic flow (EOF)-chemiluminescent devices and applied to determine transition metal ions and organic compounds. 

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