Author : Emily Morgan Harcourt
Publisher :
Page : pages
File Size : 35,37 MB
Release : 2015
Category :
ISBN :
Book Description
As our understanding of molecular biology continues to develop, both general improvements and specialized tools are needed for the progression of RNA detection and analysis. This thesis describes three distinct projects within the broad goal of expanding the techniques available for better interrogation of RNA. Chapter II illustrates the development of a new technique for microRNA detection. MicroRNAs are a class of small regulatory RNAs present in eukaryotes. MicroRNAs pose a challenge for detection because of their small size and sequence homology, but have drawn increasing interest due the predicted prevalence of their gene targets and links between their expression levels and cancer. The development of an isothermal detection strategy is described which incorporates two nucleic acid templated steps, two amplification steps, and fluorescent detection. Up to 3000-fold amplification can be obtained, and 200 pM quantities of let-7a microRNA and above can be detected reliably. In Chapter III, two distinct approaches are taken for the detection of N(6)-methyladenosine, the most common modification in RNA: harnessing base-pairing selectivity, and developing selective reactions. A successful method was developed that harnessed the inherently higher efficiency of a commercially-available polymerase, Tth DNA polymerase, when pairing T with adenosine as opposed to N(6)-methyladenosine. Kinetic analysis showed that the selectivity of the enzyme ranged from 4-18-fold, depending on sequence context. Detection of m6A in ribosomal RNA and in a highly-expressed messenger RNA are demonstrated. The final chapter focuses on a mechanistic approach for enhancing RNA recovery after formaldehyde treatment using an organocatalyst. Mass spectrometry and gel electrophoresis showed an enhanced rate of adduct reversal in the presence of the catalyst, and effects of temperature, buffer, and pH were also analyzed. The results from monomeric and oligomeric test systems have subsequently been applied to recovery of RNA from fixed samples, showing ~2-fold enhancement in recovered RNA due to the catalyst and up to 25-fold enhancement when the catalyst was used in conjunction with optimized time and temperature.