Microfluidic glass systems

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. 

B. Zheng, J.D. Tice, L.S. Roach, and R.F. Ismagilov A Droplet-Based, Composite PDMS/Glass Capillary Microfluidic System for Evaluating Protein Crystallization Conditions by Microbatch and Vapor-Diffusion Methods with on-Chip X-Ray Diffraction. Angew. Chem. Int. Ed. 43, 2508 (2004). 

The sequence includes several synthetic steps over polymer-supported catalysts in directly coupled commercially available Omnifit glass reaction columns [41] using a Syrris Africa microreactor system [14], Thales H-Cube flow hydrogenator [32] and a microfluidic chip. The process affords the alkaloid in 90% purity after solvent evaporation, but in a moderate 40% yield. After a closer investigation it was concluded that this is due to the poor yield of 50% in the phenolic oxidation step. On condition that this is resolved with the use of a more effective supported agent, the route would provide satisfactory yields and purities of the product. 

Microfluidic devices have gained importance and utility for analyses of various molecules, including drugs and their metabolites. Vrouwe et al. [151] developed NCE for point-of-care testing of lithium in blood samples. The device consisted of a glass chip coupled with a conductivity detector. The authors tested this system for lithium analysis in five patients in the hospital. Furthermore, the authors reported that sodium, lithium, magnesium, and calcium were separated in <20 seconds. The authors claimed that the NCE system provided a convenient and rapid method for point-of-care testing of electrolytes in serum and whole blood. 

Stjernstrom, M., Roeraade, J., Method for fabrication of microfluidic systems in glass. J. Micromech. Microeng. 1998, 8, 33-38. 

Xu, Z.R., Fang, Z.L., Composite poly(dimethylsiloxane)/glass microfluidic system with an immobilized enzymatic particle-bed reactor and sequential sample injection for chemiluminescence determinations. Anal. Chim. Acta 2004, 507,129-135. 

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