17 research outputs found
Digital microfluidic sample preparation for biological mass spectrometry
The use of mass spectrometry in the biosciences has undergone huge growth in re-
cent years due to sustained effort in the development of new ionisation techniques,
more powerful mass analysers and better bioinformatic tools. These developments
mean that it is now possible to introduce complex crude biological-mixtures into a
mass spectrometric platform and to obtain detailed information about the sample.
The front-end sample handling techniques used for sample preparation have, for
the most part, not changed despite the recent advances in hyphenation of liquid-
chromatography and mass spectrometry required to tackle the issue of increased
sample complexity. In this thesis the possibility of using Digital Microfluidics
(DMF) for front-end sample preparation prior to mass-spectrometric analysis of
protein samples has been investigated. DMF is a micro-electromechanical system (MEMS) technology used for manipulation of sub-microlitre droplets. The
movement of discrete droplets of liquid is exploited using the Coulombic forces
arising due to free charge polarisation. Droplets can be split, joined, dispensed
and moved over a sub-surface electrode array. In this thesis a range of DMF
devices have been designed, manufactured and coupled with mass spectrometric
platforms for protein analysis. A variety of techniques for mass spectrometry-
based analysis of biological samples from the fluidic chips have been investigated.
A robotic system has been developed to automate sample introduction, manipulation and removal. Finally the application of on-chip sample purification and
enzymatic digestion have been demonstrated, providing proof of concept for digital microfluidic sample preparation in mass spectrometry-based proteomics