Development of near real-time assessment system for cancer cells / Nahrizul Adib Kadri
Dielectrophoresis (DEP) is an electrical phenomenon that occurs when a polarisable particle is placed in non-uniform electrical fields, generating DEP force (FDEP) that is dependent upon the electrophysiological make-up of the particle in use. In cell cytometry studies, DEP offers the advantage o...
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| Summary: | Dielectrophoresis (DEP) is an electrical phenomenon that occurs when a polarisable particle is placed
in non-uniform electrical fields, generating DEP force (FDEP) that is dependent upon the
electrophysiological make-up of the particle in use. In cell cytometry studies, DEP offers the
advantage of conducting various cell manipulations in vitro without the need of specific surface
markers. Its drawbacks, namely the time-consuming processes involved and the inability to conduct
large batch cell assays, had limited its usage.
This thesis presents the work that offered solution to the said obstacles, by developing a system
capable of conducting DEP experiments within a very short period of time, thus allowing DEP effects
to be recorded close to real-time; and conducting the DEP experiments in parallel, thus allowing the
DEP effects to be recorded concurrently on multiple cell samples. This is achieved with the design
and development of programmable, multiple output waveform generator using (capable of producing
up to eight signal outputs, and extendable in multiples of four channels); improvement of planar
microelectrode device design (capable to be energised individually); design and fabrication of the
microfluidic gasket (better solution flow without localised cell collections), and design and
development of alternative DEP image analysis algorithms (capable of handling near real-time DEP
events data, and quantifying initial conditions for the light intensity).
Results from the validation studies showed that the waveform generator is capable of producing
stable, individually addressed channel outputs of up to 10 MHz at 15 Vp-p with the DEP effects
observed when the signal is supplied at a minimum of 10 seconds. The system is also capable of
handling highly conductive suspending media (up to 1.4 S/m). Validation studies using leukemic cell
lines showed the system is capable of producing near real-time DEP spectra that were consistent with
published data at a minimum temporal resolution of 60 seconds. DEP effects of the said cell
population when treated with valinomycin, a K+ ionophore, were also recorded and showed a decrease
of both membrane conductance and capacitance values as apoptosis was induced and progressed.
Declaration of Originality
This thesis and the work to which it refers are the results of my own efforts. Any ideas, data, images or text resulting from
the work of others (whether published or unpublished) are fully identified as such within the work and attributed to their
originator in the text, bibliography or in footnotes. This thesis has not been submitted in whole or in part for any other
academic degree or professional qualification. I agree that the University of Surrey has the right to submit my work to the
plagiarism detection service TurnitinUK for originality checks. Whether or not drafts have been so-assessed, the University
reserves the right to require an electronic version of the original document (as submitted) for assessment as above |
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