Quantitative mRNA detection with advanced nonlinear microscopy

Liu, Jing Ph.D., Purdue University, May 2015. Quantitative mRNA Detection with Advanced Nonlinear Microscopy. Major Professor: Joseph M.K. Irudayaraj. Cell-specific information on quantity and localization of key mRNA transcripts in single-cell level are critical to the assessment of cancer risk, therapy efficacy, and effective prevention strategies. While current techniques are not capable to visualize single mRNA transcript beyond the diffraction limit. In this thesis, two nonlinear technologies, second harmonic super-resolution microscopy (SHaSM) and transient absorption microscopy (TAM), are developed to detect and quantify single Human edimer receptor 2 (Her2) mRNA transcripts. The SHaSM is used to detect single mRNA transcript beyond the diffraction limit, while the TAM is employed to detect mRNA without the interference of fluorescence background. The thesis presents the fundamental study on the probes used in SHaSM, the concept and instrumental layout of the two technologies, and the detection as well as quantification of mRNA transcript in cells and tissues by super resolution microscopy and background-free detection microscopy. The first part of my dissertation focuses on the introduction of available mRNA detection methods and nonlinear imaging techniques. In chapter 2, I mainly characterize the SHG emission behavior of individual BTO nanocrystals via time-resolved single molecule spectroscopy, correlation spectroscopy, and confocal microscopy. High-intensity stable emission is collected from individual BTO nanocrystals with a high signal-to-noise ratio; the polar-dependent emission