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Title: Development of an automated 3D flow-focusing microfluidic platform for single cell sorting
Author: Lyu, Yingkai
ISNI:       0000 0004 9356 1148
Awarding Body: University of Glasgow
Current Institution: University of Glasgow
Date of Award: 2020
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Cell sorting from a complex and heterogeneous community represents a critical challenge in life science, biotechnology, and clinical diagnosis. To address this, fluorescence-activated cell sorting was developed several decades ago and has significantly advanced our understanding of biological systems. However, this method is not universally applicable since it requires cells to be labelled with a specific tag, which in some cases is either not desirable or not possible. In recent years, Raman-activated cell sorting (RACS) based on single cell Raman spectra has been explored as a label-free tool that can link phenotypic function with genotypic properties of cells. However, its broad implementation is limited by challenges associated with throughput and the complexity of biological systems. This thesis reports a three-dimensional flow focusing microfluidic platform for a fully automated, continuous Raman activated cell sorting (3D- RACS) that will expand the list of high throughput cell and particle sorting tools readily available to researchers in a broad range of fields. First, a proof-of-concept 3D flow-focusing device capable of both continuous and automated sorting of individual cells is developed and optimised. This flow-focusing technique is independent of the physical properties of cells and medium, which makes it a simple and generic platform for a wide variety of biological systems. Next, a complete sorting platform including the core of the 3D flow-focusing device and associated apparatus is well developed. In particular, the integration and utilization of optical sensors for the synchronisation of detection, online classification, sorting actuation and collection for subsequent processing are illustrated. Then, the development and characterisation of the platform are pursued by first using fluorescent samples (various sized beads, fluorescently labelled mammalian cells) and then Raman sorting of untagged mixtures of different types of microbes (Chlorella Vulgaris and E. coli). It is worth noting the capability of tight 3D focusing of the small E. coli (~ 1 μm) in the 1 mm3 detection chamber, since focusing such small cells in simple, soft lithography-based, large microfluidic channels (100s’ μm) remains a significant challenge. Finally, a simple “single-band” Raman microscope configuration is developed for Raman-activated sorting of the two microbes to demonstrate the deployment of a simple detection method. In summary, the sorting platform developed in this thesis will provide a versatile tool that could be used for diverse biology, biotechnology, medicine, and environmental applications.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available