Methodologies that detect biologically active substances have important
potential applications for medical diagnostics, drug discovery, and chemical and
biological anti-terrorism efforts. The wide spectrum of potential analytes that
induce a physiological response dictates that novel techniques be developed to
more rapidly screen and characterize agents that are more economical and have
greater sensitivity than current practices. The research presented in this dissertation
describes the development of a biosensor methodology that utilizes optical changes
in naturally pigmented chromatophore cells from fish to detect and measure an
array of biochemicals and protein toxins. The chromatophores used in this
biosensor were harvested from teleost fish sources and the observed patterns of
pigment aggregation and dispersion in response to added chemical modulators were
used as a reporter mechanism. Differential responses between chromatophore
subtypes were utilized as simple cellular sensors for the detection of cholera toxin
and in the study of the calcium signaling requirements in these cells.
A multi-cellular biosensor was developed that couples pigmentation
changes in erythrophores from the teleost Betta splendens with mammalian nerve
cell secretory activity. An apparatus was developed that placed PC12 cells, a
neuroendocrine cell line, and erythrophores in adjacent chambers connected by a
fluid network that allowed erythrophores to be exposed to effluent from PC12 cells;
neurotransmitters secreted from PC12 cells induced pigment aggregation in
erythrophores. By analyzing the extent of this erythrophore response, this method
was capable of detecting the occurrence of substances that altered neurotransmitter
secretion levels. A demonstration of this biosensor is presented that detected the
inhibition of neurosecretory activity caused by the pathogenic bacterial toxin
botulinum, the causative agent of human botulism. / Graduation date: 2002
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/32266 |
| Date | 02 May 2002 |
| Creators | Preston, R. Ryan |
| Contributors | McFadden, Philip N. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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