Advanced label-free cellular identification in flow by collaborative coherent imaging techniques

2019 ◽  
Author(s):  
David Dannhauser ◽  
Domenico Rossi ◽  
Maria Isabella Maremonti ◽  
Pasquale Memmolo ◽  
Pietro Ferraro ◽  
...  
Keyword(s):  
Imaging Techniques ◽  
Label Free ◽  
Coherent Imaging

scholarly journals Surface chemistry and morphology in single particle optical imaging

Nanophotonics ◽  
2017 ◽  
Vol 6 (4) ◽  
pp. 713-730 ◽  
Author(s):  
Fulya Ekiz-Kanik ◽  
Derin Deniz Sevenler ◽  
Neşe Lortlar Ünlü ◽  
Marcella Chiari ◽  
M. Selim Ünlü
Keyword(s):  
Optical Imaging ◽  
Imaging Techniques ◽  
High Specificity ◽  
Physical Structure ◽  
Dark Field ◽  
Imaging Systems ◽  
Label Free ◽  
Inhomogeneous Surface ◽  
Improve Measurement ◽  
Molecular Specificity

AbstractBiological nanoparticles such as viruses and exosomes are important biomarkers for a range of medical conditions, from infectious diseases to cancer. Biological sensors that detect whole viruses and exosomes with high specificity, yet without additional labeling, are promising because they reduce the complexity of sample preparation and may improve measurement quality by retaining information about nanoscale physical structure of the bio-nanoparticle (BNP). Towards this end, a variety of BNP biosensor technologies have been developed, several of which are capable of enumerating the precise number of detected viruses or exosomes and analyzing physical properties of each individual particle. Optical imaging techniques are promising candidates among broad range of label-free nanoparticle detectors. These imaging BNP sensors detect the binding of single nanoparticles on a flat surface functionalized with a specific capture molecule or an array of multiplexed capture probes. The functionalization step confers all molecular specificity for the sensor’s target but can introduce an unforeseen problem; a rough and inhomogeneous surface coating can be a source of noise, as these sensors detect small local changes in optical refractive index. In this paper, we review several optical technologies for label-free BNP detectors with a focus on imaging systems. We compare the surface-imaging methods including dark-field, surface plasmon resonance imaging and interference reflectance imaging. We discuss the importance of ensuring consistently uniform and smooth surface coatings of capture molecules for these types of biosensors and finally summarize several methods that have been developed towards addressing this challenge.

Structural and Biochemical Changes in Pericardium upon Genipin Cross-Linking Investigated Using Nondestructive and Label-Free Imaging Techniques

2022 ◽  
Author(s):  
Tanveer Ahmed Shaik ◽  
Enrico Baria ◽  
Xinyue Wang ◽  
Florian Korinth ◽  
João L. Lagarto ◽  
...  
Keyword(s):  
Imaging Techniques ◽  
Biochemical Changes ◽  
Cross Linking ◽  
Label Free

scholarly journals Recent advances in surface plasmon resonance imaging: detection speed, sensitivity, and portability

Nanophotonics ◽  
2017 ◽  
Vol 6 (5) ◽  
pp. 1017-1030 ◽  
Author(s):  
Youjun Zeng ◽  
Rui Hu ◽  
Lei Wang ◽  
Dayong Gu ◽  
Jianan He ◽  
...  
Keyword(s):  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Imaging Techniques ◽  
Detection Sensitivity ◽  
Label Free ◽  
Spr Biosensor ◽  
Recent Advances ◽  
Wavelength Filter ◽  
Detection Speed

AbstractSurface plasmon resonance (SPR) biosensor is a powerful tool for studying the kinetics of biomolecular interactions because they offer unique real-time and label-free measurement capabilities with high detection sensitivity. In the past two decades, SPR technology has been successfully commercialized and its performance has continuously been improved with lots of engineering efforts. In this review, we describe the recent advances in SPR technologies. The developments of SPR technologies focusing on detection speed, sensitivity, and portability are discussed in details. The incorporation of imaging techniques into SPR sensing is emphasized. In addition, our SPR imaging biosensors based on the scanning of wavelength by a solid-state tunable wavelength filter are highlighted. Finally, significant advances of the vast developments in nanotechnology-associated SPR sensing for sensitivity enhancements are also reviewed. It is hoped that this review will provide some insights for researchers who are interested in SPR sensing, and help them develop SPR sensors with better sensitivity and higher throughput.

scholarly journals Synchrotron multimodal imaging in a whole cell reveals lipid droplet core organization

2020 ◽  
Vol 27 (3) ◽  
pp. 772-778 ◽  
Author(s):  
Frédéric Jamme ◽  
Bertrand Cinquin ◽  
Yann Gohon ◽  
Eva Pereiro ◽  
Matthieu Réfrégiers ◽  
...  
Keyword(s):  
Lipid Droplet ◽  
Neutral Lipids ◽  
Imaging Techniques ◽  
Living Cells ◽  
Label Free ◽  
Steryl Esters ◽  
A Cell ◽  
Deep Ultraviolet ◽  
Auto Fluorescence ◽  
Chemical Contents

A lipid droplet (LD) core of a cell consists mainly of neutral lipids, triacylglycerols and/or steryl esters (SEs). The structuration of these lipids inside the core is still under debate. Lipid segregation inside LDs has been observed but is sometimes suggested to be an artefact of LD isolation and chemical fixation. LD imaging in their native state and in unaltered cellular environments appears essential to overcome these possible technical pitfalls. Here, imaging techniques for ultrastructural study of native LDs in cellulo are provided and it is shown that LDs are organized structures. Cryo soft X-ray tomography and deep-ultraviolet (DUV) transmittance imaging are showing a partitioning of SEs at the periphery of the LD core. Furthermore, DUV transmittance and tryptophan/tyrosine auto-fluorescence imaging on living cells are combined to obtain complementary information on cell chemical contents. This multimodal approach paves the way for a new label-free organelle imaging technique in living cells.

scholarly journals Three-dimensional label-free observation of individual bacteria upon antibiotic treatment using optical diffraction tomography

2019 ◽  
Author(s):  
Jeonghun Oh ◽  
Jea Sung Ryu ◽  
Moosung Lee ◽  
Jaehwang Jung ◽  
Seung yun Han ◽  
...  
Keyword(s):  
Imaging Techniques ◽  
Three Dimensional ◽  
Time Lapse ◽  
Optical Diffraction ◽  
Response Analysis ◽  
Diffraction Tomography ◽  
Label Free ◽  
Optical Diffraction Tomography ◽  
Quantitative Manner ◽  
Basic Studies

AbstractMeasuring alterations in bacteria upon antibiotic application is important for basic studies in microbiology, drug discovery, and clinical diagnosis, and disease treatment. However, imaging and 3D time-lapse response analysis of individual bacteria upon antibiotic application remain largely unexplored mainly due to limitations in imaging techniques. Here, we present a method to systematically investigate the alterations in individual bacteria in 3D and quantitatively analyze the effects of antibiotics. Using optical diffraction tomography, in-situ responses of Escherichia coli and Bacillus subtilis to various concentrations of ampicillin were investigated in a label-free and quantitative manner. The presented method reconstructs the dynamic changes in the 3D refractive-index distributions of living bacteria in response to antibiotics at sub-micrometer spatial resolution.

scholarly journals Computational 4D-OCM for label-free imaging of collective cell invasion and force-mediated deformations in collagen

2020 ◽  
Author(s):  
Jeffrey A. Mulligan ◽  
Lu Ling ◽  
Claudia Fischbach ◽  
Steven G. Adie
Keyword(s):  
Cancer Progression ◽  
Imaging Techniques ◽  
Traction Force ◽  
Time Lapse ◽  
Label Free ◽  
Imaging Data ◽  
Scattering Media ◽  
Current Standard ◽  
Isolated Cells ◽  
Large Tumor

AbstractTraction force microscopy (TFM) is an important family of techniques used to measure and study the role of cellular traction forces (CTFs) associated with many biological processes. However, current standard TFM methods rely on imaging techniques that do not provide the experimental capabilities necessary to study CTFs within 3D collective and dynamic systems embedded within optically scattering media. Traction force optical coherence microscopy (TF-OCM) was developed to address these needs, but has only been demonstrated for the study of isolated cells embedded within optically clear media. Here, we present computational 4D-OCM methods that enable the study of dynamic invasion behavior of large tumor spheroids embedded in collagen. Our multi-day, time-lapse imaging data provided detailed visualizations of evolving spheroid morphology, collagen degradation, and collagen deformation, all using label-free scattering contrast. These capabilities, which provided insights into how stromal cells affect cancer progression, significantly expand access to critical data about biophysical interactions of cells with their environment, and lay the foundation for future efforts toward volumetric, time-lapse reconstructions of collective CTFs with TF-OCM.

scholarly journals Holotomography: refractive index as an intrinsic imaging contrast for 3-D label-free live cell imaging

2017 ◽  
Author(s):  
Doyeon Kim ◽  
SangYun Lee ◽  
Moosung Lee ◽  
JunTaek Oh ◽  
Su-A Yang ◽  
...  
Keyword(s):  
Refractive Index ◽  
Cell Biology ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Imaging Techniques ◽  
Live Cell ◽  
Label Free ◽  
Essential Information ◽  
Research Fields ◽  
Intrinsic Imaging

AbstractLive cell imaging provides essential information in the investigation of cell biology and related pathophysiology. Refractive index (RI) can serve as intrinsic optical imaging contrast for 3-D label-free and quantitative live cell imaging, and provide invaluable information to understand various dynamics of cells and tissues for the study of numerous fields. Recently significant advances have been made in imaging methods and analysis approaches utilizing RI, which are now being transferred to biological and medical research fields, providing novel approaches to investigate the pathophysiology of cells. To provide insight how RI can be used as an imaging contrast for imaging of biological specimens, here we provide the basic principle of RI-based imaging techniques and summarize recent progress on applications, ranging from microbiology, hematology, infectious diseases, hematology, and histopathology.

Microscopy is Only Skin Deep

2011 ◽  
Vol 19 (3) ◽  
pp. 8-8
Author(s):  
Stephen W. Carmichael
Keyword(s):  
Stimulated Raman Scattering ◽  
Imaging Techniques ◽  
Chemical Species ◽  
Water Soluble ◽  
Intensity Change ◽  
Molecular Vibration ◽  
Raman Signal ◽  
Label Free ◽  
Spatiotemporal Resolution ◽  
Custom Made

Light optical imaging techniques that don't require labels are attractive for human studies because they are not toxic nor do they perturb the system being studied. Whereas there are several methods available to provide microscopic imaging below the surface of a tissue, they each suffer from limitations, such as low spatiotemporal resolution and a limited number of molecular signatures that can be imaged. Raman spectroscopy offers label-free contrast for major chemical species in tissue, such as water, lipids, DNA, and proteins based on vibrational spectra at light optical wavelengths. However, the Raman signal is very weak, which makes it difficult to image a sample with good temporal resolution. The recent development of stimulated Raman scattering (SRS) microscopy can overcome these limitations as demonstrated by the elegant studies of Brian Saar, Christian Freudiger, Jay Reichman, Michael Stanley, Gary Holton, and Sunney Xie. Saar et al. improved the optics and electronics for the acquisition of the backscattered signal of SRS. In SRS microscopy, the sample is excited by two lasers at different frequencies. When the difference in frequency matches a molecular vibration in the sample, the intensities of the probes change in a predictable manner. These intensity changes are small, but Saar et al. developed a new method to detect them. They chopped one of the laser beams at high frequency (MHz) and detected the intensity change in the other beam, which offered superior sensitivity. The key component was a custom-made all-analog lock-in amplifier with a very short (about 100 ns) response time. The laser probe wavelengths were tuned to match a vibrational frequency of interest and raster-scanned across the sample. Frequencies were tuned to detect CH2 stretching (primarily for lipids), OH stretching (primarily water), and CH3 stretching (primarily proteins) vibrations. Imaging of water is of particular interest in studying the transport of water-soluble compounds such as drugs.

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