Segmented flows in microfluidics have attracted much recent attention. Of particular interest is the use of nanolitre droplets as interface tools in microfluidics. A droplet interface connects techniques while leaving them sufficiently independent of each other; a task that difficult to perform within a continuous flow system. The first part of this thesis is dedicated to sample preparation and analysis in continuous flow microfluidic systems. The polymerase chain reaction (PCR) is investigated, using electroosmotic flow to transport the sample across various temperature zones. Additionally, a novel sieving matrix for electrophoretic separation of dsDNA fragments and PCR amplicons on microchip and capillary is demonstrated. The second part of this thesis focuses on interfacing segmented and continuous flows. Two novel interfaces are described and demonstrated. The first interface connects droplet flows and a chip-based electrophoresis device. Using this interface, samples or reactions performed in droplets can be directly transferred to a separation channel without suspending the separation. This allows multiple samples to be analysed in a single separation channel, without cross contamination between droplets. Consequently, PCR reactions and dsDNA calibration ladders can be prepared in droplet format and analysed in high throughput. The second interface links nano-liquid chromatography and MALDI mass spectrometry. Droplet fractionation post nano-LC separation is used to preserve resolution between separated bands. The droplets are subsequently delivered to a MALDI plate for mass spectrometric analysis by removing the continuous oil phase using a hydrophobic oleophilic membrane. The tools developed here reduce manual intervention and provide a link between multiple analytical techniques involved in biomolecule analysis. These innovations will improve reproducibility and reduce cross-contamination between samples.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:550912 |
| Date | January 2012 |
| Creators | Pereira, Fiona Marie |
| Contributors | de Mello, Andrew |
| Publisher | Imperial College London |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/10044/1/9302 |
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