Type of Document Dissertation Author Sinville, Rondedrick DeShaun Author's Email Address firstname.lastname@example.org URN etd-07112008-115020 Title Revolutionizing Genomic Analyses: Mutation Analyses Using Novel Enzyme-Based Assays with Laser-Induced Fluorescence and Polymeric Microfluidic Devices as Electrophoretic Platforms Degree Doctor of Philosophy (Ph.D.) Department Chemistry Advisory Committee
Advisor Name Title Steven A. Soper Committee Chair Ioan Negulescu Committee Member Robert Cook Committee Member Steve Watkins Committee Member Hollie Hale-Donze Dean's Representative Keywords
Date of Defense 2008-07-07 Availability unrestricted AbstractPolymer-based microelectrophoresis was investigated to analyze known (mutation detection) and unknown (mutation scanning) low-abundant mutations in genomic DNA with high diagnostic value for colorectal cancers. For our mutation detection assays, point mutations in the K-ras oncogene were identified using the ligase detection reaction (LDR). For the mutation scanning assay, which searches for sporadic mutations, an EndoV-LDR assay was utilized with mutations in the p53 tumor suppressor gene used as a model.
A poly(methylmethacrylate), PMMA, microchip filled with a 4% linear polyacrylamide (LPA) gel was used to electrophoretically sort products formed from LDRs, which produced oligonucleotides <65 bp in length. Using microchip electrophoresis with the LPA, a 44 bp ligation product was resolved from a 100-fold molar excess of unligated primers (25 bp) in approximately 120 s, which was ~17 times faster than conventional capillary gel electrophoresis.
In order to simplify the electrophoretic process and further reduce development time, the LDR products were sorted in the absence of the sieving gel using free solution conjugate electrophoresis (FSCE). FSCE incorporated polyamide “drag-tags” onto LDR primers, which provided DNA fragment mobilities in free solution that were dependent upon their size. LDR/drag-tagged (LDR-dt) products could be formed in a multiplexed format for mutant-to-wild-type ratios as low as 1 to 100 with single base resolution. Separations were conducted using capillary array electrophoresis (CAE) and PMMA microchips filled with only a TRIS buffer. Analysis times for the LDR-dt products were less than 11 min using CAE and ~85 s for PMMA microchips with high reproducible migration times within and between microchips.
PMMA-based microchips were also evaluated for the identification of sporadic mutations using an endonuclease V – LDR (Endo V/LDR) technique. Endo V cleaves heteroduplexed DNA one base 3’ of single-base mismatched sites as well as nicking DNA at some matched sites as LDR reseals miscleaved sites to reduce false positive signals. Results suggested that Endo V/LDR products from p53 mutations could be successfully separated and detected using a PMMA microfluidic chip filled with a sparsely cross-linked replaceable polyacrylamide gel in less than 6 min, which was approximately 10-fold shorter compared to CAE.
Filename Size Approximate Download Time (Hours:Minutes:Seconds)
28.8 Modem 56K Modem ISDN (64 Kb) ISDN (128 Kb) Higher-speed Access RSinvilleAbstract.pdf 78.20 Kb 00:00:21 00:00:11 00:00:09 00:00:04 < 00:00:01 Sinville_dis.pdf 3.80 Mb 00:17:36 00:09:03 00:07:55 00:03:57 00:00:20
If you have questions or technical problems, please Contact LSU-ETD Support.