Biological Engineering electronic theses and dissertations - Engineering (MU)The electronic theses and dissertations of the Department of Biological Engineering.https://hdl.handle.net/10355/52592024-03-29T05:02:15Z2024-03-29T05:02:15ZAccurate DNA microsatellite and microRNA detection with a biological nanoporeWang, Yingzhenhttps://hdl.handle.net/10355/700862022-09-27T15:52:10Z2019-01-01T00:00:00ZAccurate DNA microsatellite and microRNA detection with a biological nanopore
Wang, Yingzhen
[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI--COLUMBIA AT REQUEST OF AUTHOR.] Nanopore-based detection has been used in many genetic, epigenetic, proteomic, and bio-mechanism studies. In this report, we introduced two designed strategies for detecting DNA and micro-RNA with nanopore platform. First, we focused on a specific type of DNA denoted as DNA microsatellite. Microsatellite is a tandem DNA repeat unit containing one to six bases. The expansion of microsatellite always associates severe genetic disorders, such as Huntington disease (HD), Fragile X syndrome and varies kinds of cancer. In this study, we focused on a hereditary genetic disorder-Myotonic Dystrophy type I (DM1), which is caused by the expansion of CTG repeats in 3'UTR region within dystrophia myotonica protein kinase (DMPK) gene. Patients suffered from this disease always exhibited muscle atrophy as well as cognitive disorders. For now, the commonly used diagnostic approaches for DM1 are PCR and Southern blot. However, the efficiency and accuracy of PCR are restricted by the sequence length, and Southern blot is limited by the sample loads. Although DNA sequencing develops rapidly in recent years, the precision of detecting long tandem repeats still remains a problem. Also, sequencing is not necessary for diagnostic purpose. In this report, we presented a novel approach using nanopore technology. The double strand DNAs bound to Hg2+ to form different numbers of nanolocks. By adding an overhang sequence to the target strand, long double strand DNAs were able to unzip outside the nanopore and generate distinguishable duration histogram. In this case, we successfully linked the lengths of CTG repeats with the numbers of nanolocks
2019-01-01T00:00:00ZAmyloid- [beta] peptide induces temporal membrane biphasic changes in astrocytes through cytosolic phospholipase A₂Hicks, Jacobhttps://hdl.handle.net/10355/80962022-09-27T15:51:44Z2010-01-01T00:00:00ZAmyloid- [beta] peptide induces temporal membrane biphasic changes in astrocytes through cytosolic phospholipase A₂
Hicks, Jacob
Oligomeric amyloid-[beta] peptide (A[beta]) is known to induce cytotoxic effects and damage cell functions in Alzheimer's disease. However, mechanisms underlying the effects of A[beta] on cell membranes have yet to be fully elucidated. In this study, A[beta] 1-42 (A[beta][subscript 42]) was shown to cause a temporal biphasic change in membranes of astrocytic DITNC cells using fluorescence microscopy of Laurdan. A[beta][subscript 42] made astrocyte cell membranes become more molecularly-disordered after 30 minutes to 1 hour, transitioning to more molecularly-ordered after 3 hours. However, A[beta][subscript 42] caused artificial vesicle membranes made of rat whole brain lipid extract to become more disordered only. The trend for more molecularly-ordered membranes in astrocytes was abrogated by either an NADPH oxidase inhibitor, apocynin, or an inhibitor of cytosolic phospholipase A[subscript 2] (cPLA[subscript 2]), but not by an inhibitor of calcium-independent PLA2 (iPLA[subscript 2]). Apocynin also suppressed the increased production of superoxide anions (O[subscript 2]-) and phosphorylation of cPLA[subscript 2] induced by A[beta][subscript 42]. In addition, hydrolyzed products of cPLA[subscript 2], arachidonic acid (AA), but not lysophosphatidylcholine (LPC) caused astrocyte membranes to become more molecularly-ordered. These results suggest (1) a direct interaction of A[beta][subscript 42] with cell membranes making them more molecularly-disordered, and (2) A[beta][subscript 42] indirectly makes membranes become more molecularly-ordered by triggering the signaling pathway involving NADPH oxidase and cPLA[subscript 2].
Title from PDF of title page (University of Missouri--Columbia, viewed on June 14, 2010).; The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.; Thesis advisor: Dr. James Lee.; M.S. University of Missouri--Columbia 2010.
2010-01-01T00:00:00ZApplications of gel electrophoresis in quantum dot conjugates' separation and purificationWang, Luxin, 1983-https://hdl.handle.net/10355/64862023-02-14T21:34:42Z2009-01-01T00:00:00ZApplications of gel electrophoresis in quantum dot conjugates' separation and purification
Wang, Luxin, 1983-
The objectives of this study were to build Quantum dot (QD) crosslinker complexes for antibody conjugation usage, to purify QD crosslinker complexes by gel electrophoresis and to check the biological functionalities of eluted QD crosslinker complexes recovered from gel electrophoresis by cell based microarray. Zero-length crosslinker 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) was chosen to be the first crosslinkers, followed by the conjugation with secondary crosslinker protein A. The purpose of adding secondary crosslinkers was to make uniform QD crosslinker complexes. Due to the high affinity between protein A and the Fc region of antibodies, QD EDC protein A complexes were in uniform structures and all antigen binding sites faced outwardly. Gel electrophoresis is a method used for separating DNA, RNA or proteins in biological studies. In this study, gel electrophoresis was adopted to check the complete conjugation between QDs and protein A. In addition, it was successfully used as a separation method for purifying conjugated QDs. GeBaflex tubes were used to elute the conjugated QDs from the gel, these recovered QD EDC protein A complexes showed their biological functionalities in cell based microarray studies.
Title from PDF of title page (University of Missouri--Columbia, viewed on Feb 19, 2010).; The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.; Thesis advisor: Dr. Xudong Fan and Dr. Azlin Mustapha.; M.S. University of Missouri--Columbia 2009.
2009-01-01T00:00:00ZApplications of the opto-fluidic ring resonator for DNA methylation analysis and microfluidic laser developmentSuter, Jonathan Daniel, 1982-https://hdl.handle.net/10355/102482022-09-27T15:49:57Z2010-01-01T00:00:00ZApplications of the opto-fluidic ring resonator for DNA methylation analysis and microfluidic laser development
Suter, Jonathan Daniel, 1982-
For several decades, optical ring resonators have played an important role in the field of telecommunications. Within only the past decade however, ring resonators have been applied for the purposes of biological and chemical detection by means of refractometric signal transduction. The advantage of ring resonator-based sensing is that, unlike fluorescence detection, it is label-free and can yield quantitative data. This document presents the fundamental operation of the versatile opto-fluidic ring resonator (OFRR) and explores its applications in DNA methylation analysis. Using affinity assays based on anti-5-methyl cytosine antibodies as well as the methyl binding protein MBD-2, it is shown that the OFRR is a promising tool for biomedical research that can discriminate the extent of DNA methylation. As a part of evolving this and other devices towards a practical laboratory and clinical tool, it is important to consider methods for integrating optical functionality onto a compact chip. Towards this end, we also investigate the ability of PDMS-based ring resonators to provide tunable on-chip microfluidic lasers. This idea is explored by looking at two different ring geometries. Very low lasing thresholds are demonstrated.
Title from PDF of title page (University of Missouri--Columbia, viewed on December 7, 2010).; The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.; Dissertation advisor: Dr. Xudong Fan.; Vita.; Ph. D. University of Missouri--Columbia 2010.
2010-01-01T00:00:00Z