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Biomedical Engineering and Bioengineering

Washington University in St. Louis

Fluorescence

Articles 1 - 3 of 3

Full-Text Articles in Engineering

6d Single-Fluorogen Orientation-Localization Microscopy For Elucidating The Architecture Of Beta-Sheet Assemblies And Biomolecular Condensates, Tingting Wu, Weiyan Zhou, Jai S. Rudra, Rohit V. Pappu, Matthew D. Lew Mar 2024

6d Single-Fluorogen Orientation-Localization Microscopy For Elucidating The Architecture Of Beta-Sheet Assemblies And Biomolecular Condensates, Tingting Wu, Weiyan Zhou, Jai S. Rudra, Rohit V. Pappu, Matthew D. Lew

Electrical & Systems Engineering Publications and Presentations

We develop six-dimensional single-molecule orientation-localization microscopy (SMOLM) to measure the 3D positions and 3D orientations simultaneously of single fluorophores. We show how careful optimization of phase and polarization modulation components can encode phase, polarization, and angular spectrum information from each fluorescence photon into a microscope’s dipole-spread function. We used the transient binding and blinking of Nile red (NR) to characterize the helical structure of fibrils formed by designed amphipathic peptides, KFE8L and KFE8D, and the pathological amyloid-beta peptide Aβ42. We also deployed merocyanine 540 to uncover the interfacial architectures of biomolecular condensates.


Comparison Of In-Vitro 3d Human Embryoids With Current Models For Gastrulation, Jin Park Jan 2023

Comparison Of In-Vitro 3d Human Embryoids With Current Models For Gastrulation, Jin Park

McKelvey School of Engineering Theses & Dissertations

Gastrulation is an early morphogenetic process that is conserved across most metazoans and lays out the future body plan through the formation and shaping of the three germ layers: endoderm, mesoderm, and ectoderm. Despite its importance, not much is known about the events surrounding human gastrulation that occurs in utero due to ethical and technical limitations on studying human embryos. Therefore, many researchers have devised protocols for creating in vitro models of gastrulation using embryonic stem cells. Initially starting with mouse embryonic stem cells, the field of in vitro embryo models has advanced rapidly, with protocols using human embryonic stem …


Measuring G Protein Activation With Spectrally Resolved Fluorescence Fluctuation Spectroscopy, Daniel Foust Aug 2022

Measuring G Protein Activation With Spectrally Resolved Fluorescence Fluctuation Spectroscopy, Daniel Foust

McKelvey School of Engineering Theses & Dissertations

Fluorescence fluctuation spectroscopy (FFS) is comprised of a set of statistical techniques used to learn information about fluorescence particles by analyzing intensity fluctuations in signals detected from a fluorescence spectrometer or microscope. In biological contexts, FFS is commonly used to quantify the concentrations, molecular brightnesses, and transport properties (e.g. diffusion coefficients) of labeled biomolecules. In particular, the molecular brightness parameter is valuable because it can be used to quantify oligomerization of biomolecules. Therefore, FFS has emerged as an attractive tool for measuring protein-protein interactions in live cells. This dissertation describes the development of image-based, multicolor FFS techniques. Image-based FFS is …