Biology subjects

Brenner, B.

Publications and source records attributed to Brenner, B..

6 recordsLinked to original sources

bioRxiv2024

Implementation and calibration of spectroscopic single-molecule localization microscopy

Spectroscopic single-molecule localization microscopy (sSMLM) allows multi-color super-resolution images with high spectral sensitivity. In this protocol, we provide essential information for researchers to implement sSMLM in a laboratory setting. We describe how to assemble and align the illumination and detection paths of a 3D dual-wedge prism (DWP)-based sSMLM instrument. We provide detailed step-by-step instructions for performing spectral and axial calibration using fluorescent beads and a nanohole array, respectively. We also discuss using sSMLM to image fluorescently labeled cells and report a new MATLAB package, RainbowSTORM v2, to reconstruct super-resolution 3D images. Further, we present representative images as typical anticipated results for users to validate.

bioengineering↗

bioRxiv2024

Maximizing photon utilization in spectroscopic single-molecule localization microscopy using symmetrically dispersed dual-wedge prisms

Single-molecule localization microscopy (SMLM) enables super-resolution imaging on conventional fluorescent microscopes. Spectroscopic SMLM (sSMLM) further allows highly multiplexed super-resolution imaging. We report an easy-to-implement symmetrically dispersed dual-wedge prism (SDDWP)-sSMLM design that maximizes photon utilization. We first symmetrically dispersed photons to the -1st and +1st orders in an optical assembly using two identical dual-wedge prisms (DWPs). Then we computationally extracted the fluorophores spatial position and spectral characteristics using photons in both the -1st and +1st orders. Theoretical analysis and experimental validation showed lateral and spectral precisions of 10.1 nm and 0.3 nm, respectively, representing improvements of 28% and 48% over our previous DWP-based system, where emitted photons are divided separately for spatial and spectral analyses.

bioengineering↗

bioRxiv2023

Multiscale imaging of corneal endothelium damage and effects of Rho Kinase inhibitor application in mouse models of acute ocular hypertension

We developed a multiscale optical imaging workflow, integrating and correlating visible-light optical coherence tomography, confocal laser scanning microscopy, and single-molecule localization microscopy to investigate the mouse cornea damages from the in-vivo tissue level to the nanoscopic single-molecule level. We used electron microscopy to validate the imaged nanoscopic structures. We imaged wild-type mice and mice with acute ocular hypertension and examined the effects of Rho Kinase inhibitor application. We defined four types of intercellular tight junction structures as healthy, compact, partially-distorted, and fully-distorted types by labeling the Zonula occludens-1 protein in the corneal endothelial cell layer. We correlated the statistics of the four types of tight junction structures with cornea thickness and intraocular pressure. We found that the population of fully-distorted tight junctions correlated well with the level of cornea edema, and applying Rho Kinase inhibitor reduced the population of fully-distorted tight junctions under acute ocular hypertension.

biophysics↗

bioRxiv2023

Quantify nanoscopic alterations associated with mitochondrial dysfunctions using three-dimensional single-molecule localization microscopy

The morphology of mitochondria provides insights into their functions. Three-dimensional (3D) single-molecule localization microscopy (SMLM) uniquely enables the analysis of mitochondrial morphological features individually, thanks to its high resolution. However, nearly all reported studies of mitochondrial morphology have been qualitative and without statistical analysis. We report a quantitative method to extract mitochondrial morphological metrics, including volume, aspect ratio, and local protein density, from 3D SMLM images, with single-mitochondrion sensitivity. We validated our approach using simulated ground-truth SMLM images of mitochondria. We further tested our morphological analysis on mitochondria that have been altered functionally and morphologically in controlled manners. This work sets the stage to analyze mitochondrial morphological alterations associated with disease progression quantitatively.

biophysics↗

bioRxiv2022

Altered somatic hypermutation patterns in COVID-19 patients classifies disease severity

The success of the human body in fighting SARS-CoV-2 infection relies on lymphocytes and their antigen receptors. Identifying and characterizing clinically relevant receptors is of utmost importance. We report here the application of a machine learning approach, utilizing B cell receptor repertoire sequencing data from severely and mildly infected individuals with SARS-CoV-2 compared with uninfected controls. In contrast to previous studies, our approach successfully stratifies non-infected from infected individuals, as well as disease level of severity. The features that drive this classification are based on somatic hypermutation patterns, and point to alterations in the somatic hypermutation process in COVID-19 patients. These features may be used to build and adapt therapeutic strategies to COVID-19, in particular to quantitatively assess potential diagnostic and therapeutic antibodies. These results constitute a proof of concept for future epidemiological challenges.

immunology↗

bioRxiv2019

Symmetrically-dispersed spectroscopic single-molecule localization microscopy

Spectroscopic single-molecule localization microscopy (sSMLM) achieved simultaneously imaging and spectral analysis of single molecules for the first time. Current sSMLM fundamentally suffers from reduced photon budget because of dividing photons from individual stochastic emission into spatial and spectral channels. Therefore, both spatial localization and spectral analysis only use a portion of the total photons, leading to reduced precisions in both channels. To improve the spatial and spectral precisions, we present symmetrically-dispersed sSMLM or SDsSMLM to fully utilize all photons from individual stochastic emissions in both spatial and spectral channels. SDsSMLM achieved 10-nm spatial and 0.8-nm spectral precisions at a total photon budget of 1000. Comparing with existing sSMLM using a 1:3 splitting ratio between spatial and spectral channels, SDsSMLM improved the spatial and spectral precisions by 42% and 10%, respectively, under the same photon budget. We also demonstrated multi-color imaging in fixed cells and three-dimensional single-particle tracking using SDsSMLM.

biophysics↗