scholarly journals Advanced Label-Free Optical Methods for Spermatozoa Quality Assessment and Selection

2018 ◽  
Author(s):  
Annalisa De Angelis ◽  
Maria Antonietta Ferrara ◽  
Giuseppe Coppola ◽  
Anna Chiara De Luca
Keyword(s):  
Quality Assessment ◽  
Optical Methods ◽  
Label Free

scholarly journals Volumetric registration of magnetic nanoparticles for optimization of quantitative immunochromatographic assays for detection of small molecules

2018 ◽  
Vol 185 ◽  
pp. 10006 ◽  
Author(s):  
Natalia V. Guteneva ◽  
Sergey L. Znoyko ◽  
Alexey V. Orlov ◽  
Maxim P. Nikitin ◽  
Petr I. Nikitin
Keyword(s):  
Magnetic Nanoparticles ◽  
Small Molecules ◽  
Optical Methods ◽  
Magnetic Method ◽  
Label Free ◽  
Spectral Correlation ◽  
Entire Volume ◽  
Specificity And Sensitivity ◽  
Particle Quantification

Precise quantitative and highly sensitive detection of small molecules (haptens) is highly demanded in medicine, food quality control, in vitro diagnostics, criminalistics, environmental monitoring, etc. In the present work, the magnetic method of particle quantification and the optical methods of spectral correlation and spectral phase interferometry complement each other for optimization of a quantitative assay for measuring concentrations of small molecules. The assay employs magnetic nanoparticles as labels in rapid immunochromatographic format. The approach was demonstrated with fluorescein as a model molecule. The interferometric label-free biosensors were employed for selection of optimal reagents that produced high specificity and sensitivity. The method of magnetic particle quantification counted the magnetic labels over the entire volume of the immunochromatographic membrane to provide their distribution along the test strip. Such distribution was used for optimization of such parameters as concentrations of the used reagents and of antibody immobilized on the labels, amount of the labels and conjugates of haptens with protein carriers to realize the advanced quantitative immunochromatographic assay.

scholarly journals Immune cell type, cell activation, and single cell heterogeneity revealed by label-free optical methods

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Nicolas Pavillon ◽  
Nicholas I. Smith
Keyword(s):  
Single Cell ◽  
Cell Activation ◽  
Immune Cell ◽  
Global Analysis ◽  
Measurement Techniques ◽  
Optical Methods ◽  
Phase Imaging ◽  
Label Free ◽  
Experimental Conditions ◽  
Culturing Conditions

AbstractMeasurement techniques that allow the global analysis of cellular responses while retaining single-cell sensitivity are increasingly needed in order to understand complex and dynamic biological processes. In this context, compromises between sensitivity, degree of multiplexing, throughput, and invasiveness are often unavoidable. We present here a noninvasive optical approach that can retrieve quantitative biomarkers of both morphological and molecular phenotypes of individual cells, based on a combination of quantitative phase imaging and Raman spectroscopy measurements. We then develop generalized statistical tools to assess the influence of both controlled (cell sub-populations, immune stimulation) and uncontrolled (culturing conditions, animal variations, etc.) experimental parameters on the label-free biomarkers. These indicators can detect different macrophage cell sub-populations originating from different progenitors as well as their activation state, and how these changes are related to specific differences in morphology and molecular content. The molecular indicators also display further sensitivity that allow identification of other experimental conditions, such as differences between cells originating from different animals, allowing the detection of outlier behaviour from given cell sub-populations.

scholarly journals Label-free and Multimodal Second Harmonic Generation Light Sheet Microscopy

2020 ◽  
Author(s):  
Niall Hanrahan ◽  
Simon I. R. Lane ◽  
Peter Johnson ◽  
Konstantinos Bourdakos ◽  
Christopher Brereton ◽  
...  
Keyword(s):  
Second Harmonic Generation ◽  
Harmonic Generation ◽  
Biological Samples ◽  
3D Imaging ◽  
Second Harmonic ◽  
Three Dimensional ◽  
Light Sheet ◽  
Optical Methods ◽  
Label Free ◽  
Light Sheet Microscopy

AbstractLight sheet microscopy (LSM) has emerged as one of most profound three dimensional (3D) imaging tools in the life sciences over the last decade. However, LSM is currently performed with fluorescence detection on one- or multi-photon excitation. Label-free LSM imaging approaches have been rather limited. Second Harmonic Generation (SHG) imaging is a label-free technique that has enabled detailed investigation of collagenous structures, including its distribution and remodelling in cancers and respiratory tissue, and how these link to disease. SHG is generally regarded as having only forward- and back-scattering components, apparently precluding the orthogonal detection geometry used in Light Sheet Microscopy. In this work we demonstrate SHG imaging on a light sheet microscope (SHG-LSM) using a rotated Airy beam configuration that demonstrates a powerful new approach to direct, without any further processing or deconvolution, 3D imaging of harmonophores such as collagen in biological samples. We provide unambiguous identification of SHG signals on the LSM through its wavelength and polarisation sensitivity. In a multimodal LSM setup we demonstrate that SHG and two-photon signals can be acquired on multiple types of different biological samples. We further show that SHG-LSM is sensitive to changes in collagen synthesis within lung fibroblast 3D cell cultures. This work expands on the existing optical methods available for use with light sheet microscopy, adding a further label-free imaging technique which can be combined with other detection modalities to realise a powerful multi-modal microscope for 3D bioimaging.

scholarly journals Monitoring the molecular composition of live cells exposed to electric pulses via label-free optical methods

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Antoine Azan ◽  
Marianne Grognot ◽  
Tomás García-Sánchez ◽  
Lucie Descamps ◽  
Valérie Untereiner ◽  
...  
Keyword(s):  
Molecular Composition ◽  
Optical Methods ◽  
Live Cells ◽  
Label Free ◽  
Electric Pulses

Advanced Approaches to Diagnose and Treat the Chronic Autoimmune Disorders

2016 ◽  
pp. 70-98
Author(s):  
Tomasz Sołtysiński
Keyword(s):  
Immune System ◽  
Imaging Spectroscopy ◽  
Ultrasonic Waves ◽  
Optical Methods ◽  
Label Free ◽  
Experimental Systems ◽  
Cell Measurement ◽  
Living Organisms ◽  
On Chip ◽  
Molecular Components

Pathology and dynamics of particular cells and the molecular components of immune system is still challenging to be traced within living organisms. The techniques of molecular imaging (MI) are promising tools to monitor the immune system at work, to improve or allow personalized diagnostics and treatment, especially of the autoimmune diseases. In this study some possible targets for MI and biosensing are discussed. The personalized medicine, in addition to bioinformatics-based systemic approach, requires extensive research and novel high-throughput technologies like next generation of imaging, biosensing experimental systems based on microfluidics, nanotechnology, femtochemistry, superresolution (STED, STORM, PALM, SOFI, etc.), label-free imaging, spectroscopy (including TCSPC), MRI, multimodal optical methods, accoustic imaging through ultrasonic waves, nuclear medicine methods like SPECT and PET. Moreover, dedicated designs of modular Lab-on-Chip solutions are of high demand to perform multipurpose cell measurement and give a possibility to flexibly interact with sensed objects.

scholarly journals Polarimetric Measurements of Surface Chirality Based on Linear and Nonlinear Light Scattering

2021 ◽  
Vol 8 ◽  
Author(s):  
Ankur Gogoi ◽  
Surajit Konwer ◽  
Guan-Yu Zhuo
Keyword(s):  
Conformational Changes ◽  
Nonlinear Optical ◽  
Building Blocks ◽  
Mirror Image ◽  
Optical Methods ◽  
Label Free ◽  
Chiral Drugs ◽  
Critical Issues ◽  
Linear And Nonlinear ◽  
Nonlinear Light Scattering

A molecule, molecular aggregate, or protein that cannot be superimposed on its mirror image presents chirality. Most living systems are organized by chiral building blocks, such as amino acids, peptides, and carbohydrates, and any change in their molecular structure (i.e., handedness or helicity) alters the biochemical and pharmacological functions of the molecules, many of which take place at surfaces. Therefore, studying surface chirogenesis at the nanoscale is fundamentally important and derives various applications. For example, since proteins contain highly ordered secondary structures, the intrinsic chirality can be served as a signature to measure the dynamics of protein adsorption and protein conformational changes at biological surfaces. Furthermore, a better understanding of chiral recognition and separation at bio-nanointerfaces is helpful to standardize chiral drugs and monitor the synthesis of adsorbents with high precision. Thus, exploring the changes in surface chirality with polarized excitations would provide structural and biochemical information of the adsorbed molecules, which has led to the development of label-free and noninvasive measurement tools based on linear and nonlinear optical effects. In this review, the principles and selected applications of linear and nonlinear optical methods for quantifying surface chirality are introduced and compared, aiming to conceptualize new ideas to address critical issues in surface biochemistry.

Covalent grafting of graphene oxide on functionalized macroporous silicon

2018 ◽  
Vol 4 (1) ◽  
pp. 15-22 ◽  
Author(s):  
Rosalba Moretta ◽  
Monica Terracciano ◽  
Principia Dardano ◽  
Maurizio Casalino ◽  
Ilaria Rea ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Hybrid Structure ◽  
Optical Methods ◽  
Single Atom ◽  
Macroporous Silicon ◽  
Label Free ◽  
Water Contact ◽  
Force Microscopy ◽  
Atomic Force ◽  
Covalent Grafting

Abstract Graphene oxide (GO) is a single-atom-thick and two-dimensional carbon material that has attracted great attention because of its remarkable electronic, mechanical, chemical and thermal properties. GO could be an ideal substrate for the development of label-free optical biosensors, however, its weak photoluminescence (PL) strongly limits the use for this purpose. In this study, we developed a covalent chemical strategy in order to obtain a hybrid GO-macroporous silicon (PSi) structure for biomedical applications. The realized structure was characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM)water contact angle (WCA) measurements, Fourier transform infrared spectroscopy (FTIR) and label- free optical methods based on spectroscopic reflectometry and PL analysis. Investigations showed that the hybrid structure is suitable as a transducer material for biosensing applications due to its peculiar optical properties resulting from the combination of GO and PSi.

scholarly journals A large size-selective DNA nanopore with sensing applications

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Rasmus P. Thomsen ◽  
Mette Galsgaard Malle ◽  
Anders Hauge Okholm ◽  
Swati Krishnan ◽  
Søren S.-R. Bohr ◽  
...  
Keyword(s):  
Lipid Bilayers ◽  
Single Molecule ◽  
Detection System ◽  
Optical Methods ◽  
Label Free ◽  
Sensing Applications ◽  
Large Size ◽  
Transmission Electron ◽  
Label Free Detection ◽  
External Signals

AbstractTransmembrane nanostructures like ion channels and transporters perform key biological functions by controlling flow of molecules across lipid bilayers. Much work has gone into engineering artificial nanopores and applications in selective gating of molecules, label-free detection/sensing of biomolecules and DNA sequencing have shown promise. Here, we use DNA origami to create a synthetic 9 nm wide DNA nanopore, controlled by programmable, lipidated flaps and equipped with a size-selective gating system for the translocation of macromolecules. Successful assembly and insertion of the nanopore into lipid bilayers are validated by transmission electron microscopy (TEM), while selective translocation of cargo and the pore mechanosensitivity are studied using optical methods, including single-molecule, total internal reflection fluorescence (TIRF) microscopy. Size-specific cargo translocation and oligonucleotide-triggered opening of the pore are demonstrated showing that the DNA nanopore can function as a real-time detection system for external signals, offering potential for a variety of highly parallelized sensing applications.

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