A5013134305- Advanced Fluorescence Microscopy Techniques
- Cell Image Analysis Techniques
- Bacterial biofilms and quorum sensing
- Lipid Membrane Structure and Behavior
- Optical Imaging and Spectroscopy Techniques
- Spectroscopy and Quantum Chemical Studies
- Photosynthetic Processes and Mechanisms
- Proteoglycans and glycosaminoglycans research
- Spectroscopy Techniques in Biomedical and Chemical Research
- Advanced Electron Microscopy Techniques and Applications
- Antimicrobial Peptides and Activities
- Cellular Mechanics and Interactions
- Mathematical Biology Tumor Growth
- Sepsis Diagnosis and Treatment
- Advanced Biosensing Techniques and Applications
- Blood properties and coagulation
- Bacterial Identification and Susceptibility Testing
- Cystic Fibrosis Research Advances
- Respiratory Support and Mechanisms
- Glycosylation and Glycoproteins Research
- ATP Synthase and ATPases Research
- Graphene and Nanomaterials Applications
- Supramolecular Self-Assembly in Materials
- Aquaculture disease management and microbiota
- Erythrocyte Function and Pathophysiology
Agency for Science, Technology and Research
2023-2024
Genome Institute of Singapore
2021-2024
National University of Singapore
2010-2022
RELX Group (United States)
2020
National University Health System
2019
Singapore-MIT Alliance for Research and Technology
2008-2013
Nanyang Technological University
2012-2013
Abstract Molecular diffusion in biological membranes is a determining factor cell signaling and function. In the past few decades, three main fluorescence spectroscopy techniques have emerged that are capable of measuring molecular artificial at very different concentration ranges spatial resolutions. The widely used methods recovery after photobleaching (FRAP) single‐particle tracking (SPT) can determine absolute coefficients high (>100 μm −2 ) low surface concentrations (single‐molecule...
The electronic properties of graphene can be modulated by charged lipid bilayer adsorbing on the surface. Biorecognition events which lead to changes in membrane integrity monitored electrically using an electrolyte-gated biomimetic membrane−graphene transistor. Here, we demonstrate that bactericidal activity antimicrobial peptides sensed based a complex interplay biomolecular doping and ionic screening effect.
The life sciences require new highly sensitive imaging tools, which allow the quantitative measurement of molecular parameters within a physiological three-dimensional (3D) environment. Therefore, we combined single plane illumination microscopy (SPIM) with camera based fluorescence correlation spectroscopy (FCS). SPIM-FCS provides contiguous particle number and diffusion coefficient images high spatial resolution in homo- heterogeneous 3D specimens live zebrafish embryos. Our recorded up to...
Imaging fluorescence correlation spectroscopy (FCS) performed using array detectors has been successfully used to quantify the number, mobility, and organization of biomolecules in cells organisms. However, there have not any systematic studies on errors these estimates that are introduced due instrumental experimental factors. State-of-the-art still restricted number frames can be recorded per unit time, sensitivity noise characteristics, total realistically recorded. These limitations...
Abstract Super-resolution microscopy and single molecule fluorescence spectroscopy require mutually exclusive experimental strategies optimizing either temporal or spatial resolution. To achieve both, we implement a GPU-supported, camera-based measurement strategy that highly resolves structures (~100 nm), dynamics (~2 ms), molecular brightness from the exact same data set. Simultaneous super-resolution of details leads to an improved precision in estimating diffusion coefficient actin...
The multiplexing of fluorescence correlation spectroscopy (FCS), especially in imaging FCS using fast, sensitive array detectors, requires the handling large amounts data. One can easily collect excess 100,000 curves a day, too many to be treated manually. Therefore, ImFCS, an open-source software which relies on standard image files was developed and provides wide range options for calculation spatial temporal auto- cross-correlations, as well differences Cross-Correlation Functions (ΔCCF)....
Abstract Camera‐based fluorescence correlation spectroscopy (FCS) approaches allow the measurement of thousands contiguous points yielding excellent statistics and details sample structure. Imaging total internal reflection FCS (ITIR‐FCS) provides these measurements on lipid membranes. Herein, we determine influence point spread function (PSF) optical system, laser power used, time resolution camera accuracy diffusion coefficient concentration measurements. We demonstrate that PSF can be...
The local hemodynamic shear stress waveforms present in an artery dictate the endothelial cell phenotype. observed decrease of apical glycocalyx layer on endothelium atheroprone regions circulation suggests that may have a central role determining atherosclerotic plaque formation. However, kinetics for cells' ability to adapt its environment not been quantitatively resolved. Here we report heparan sulfate component HUVECs increases by 1.4-fold following onset high stress, compared static...
The influence of the biofilm matrix on molecular diffusion is commonly hypothesized to be responsible for emergent characteristics biofilms such as nutrient trapping, signal accumulation and antibiotic tolerance. Hence quantifying coefficient important determine whether there an microenvironment mobility molecules. Here, we use single plane illumination microscopy fluorescence correlation spectroscopy (SPIM-FCS) obtain 3D maps with micrometre spatial millisecond temporal resolution entire...
Fluorescence spectroscopy has been a cornerstone of research in membrane dynamics and organization. Technological advances fluorescence went hand with discovery various physicochemical properties membranes at nanometric spatial microsecond timescales. In this perspective, we discuss the challenges associated quantification how modes have overcome these to shed light on structure organization membranes. Finally, newer measurement strategies data analysis tools investigate structure, dynamics,
Morphogenesis is controlled by signalling morphogens that form gradients across the embryo. The gradient formation requires low molecular weight slow down their diffusion at least one order of magnitude. However, precise slow-down relevant micrometre scales has not been directly observed. Here, we develop and employ Single-Plane Illumination Microscope based spatial Fluorescence Cross-Correlation Spectroscopy (SPIM-sFCCS) to measure coefficient morphogen Squint in early zebrafish embryos as...
Imaging fluorescence correlation spectroscopy (FCS) and the related FCS diffusion law have been applied in recent years to investigate modes of lipids proteins membranes. These efforts provided new insights into membrane structure below optical diffraction limit, information on existence lipid domains, influence cytoskeleton dynamics. However, there has no systematic study evaluate how domain size, density, probe partition coefficient affect resulting imaging parameters. Here, we...
Number and brightness (N&B) analysis is a fluorescence spectroscopy technique to quantify oligomerization of the mobile fraction proteins. Accurate results, however, rely on good knowledge nonfluorescent states fluorescent labels, especially proteins, which are widely used in biology. Fluorescent proteins have been characterized for confocal, but not camera-based, N&B, allows, principle, faster measurements over larger areas. Here, we calibrate camera-based N&B implemented total internal...
Molecular mechanisms by which sex steroids interact with P. aeruginosa to modulate its virulence have yet be reported. Our work provides the first characterization of a steroid-induced membrane stress mechanism promoting virulence, includes release proinflammatory outer vesicles, resulting in inflammation, host tissue damage, and reduced bacterial clearance. We further demonstrate that at nanomolar (physiological) concentrations, male female promote clinical strains based on their dynamic...
Oxygen is required for respiration in aerobic bacteria and hence plays an essential role the generation of energy necessary cell maintenance growth. The distribution oxygen within a biofilm can be heterogeneous may result bacterial cells exhibiting distinct physiological states depending on their local availability. Here, we have employed transient state (TRAST) monitoring, non-invasive method that measure relative populations triplet by time-modulated illumination, to determine...
Abstract Fluorescence correlation spectroscopy (FCS) is a well-established single-molecule method used for the quantitative spatiotemporal analysis of dynamic processes in wide range samples. It possesses sensitivity but provides ensemble averaged molecular parameters such as mobility, concentration, chemical reaction kinetics, photophysical properties and interaction properties. These have been utilized to characterize variety soft matter systems. This review an overview basic principles...
Abstract We describe a protocol for the preparation of live cell samples fluorescence spectroscopy and computational super-resolution imaging. detail here how to culture, transfect, prepare cells applications.
Abstract We describe here a protocol for performing simultaneous spatiotemporal computational super-resolution and multi-parametric fluorescence microscopy. Our approach does not need specialized instrumentation, utilizes GPU faster data evaluation, produces mutually consistent structure dynamics data.
The objective of this study was to observe sphingolipid behavior in cell membranes. For this, we generated the ganglioside‐binding probes SBD ( S phingolipid B inding D omain), derived from Alzheimer's Aß peptide, and TeNT46, Tetanus toxin. Both these peptides display slow, bimodal diffusion at membranes typical for ordered domain (l o ) probes, but show different lipid requirements binding slow diffusion. Fluorescence correlation spectroscopy (FCS) has sufficient time resolution follow...