Novel Label-Free Cells Structure Detection Method Study Based on Mie Scattering Principle

2012 ◽  
Vol 591-593 ◽  
pp. 1800-1804
Author(s):  
Lu Zhang ◽  
Zong Yao Li ◽  
Hong Zhao ◽  
Wei Chen ◽  
Li Yuan ◽  
...  
Keyword(s):  
Light Intensity ◽  
Incident Angle ◽  
Mie Scattering ◽  
Label Free ◽  
Structure Information ◽  
Scattering Spectrum ◽  
Structure Detection ◽  
Free Cells ◽  
Important Diagnostic Tool ◽  
Health Situation

Cell health situation relates to its inter structures closely. Cell scattering measurement can be a non-invasive measurement method to obtain cells structure information. But normal scattering detection by original scattering spectrum can not identify cells inner structure changing, such as nucleus radii difference. Traditional scattering spectrum analysis method for identifying cells is to plot the forward scattering (FS) light intensity against side scattering (SS) light intensity. Overlapping phenomenon always occurs which leads to serious error or even mistakes in cells identification results. The Novel even scattering angle superposition algorithm and even incident angle superposition algorithm are put forward herein. In this way, the same kind of cells with different inner structures can be effectively distinguished. The rapid, convenient and label-free cells assorting and detecting can be therefore well accomplished, and these novel methods could be a kind of important diagnostic tool in cancer or other malignant cells diagnosis.

scholarly journals NMR-Based Structural Characterization of a Two-Disulfide-Bonded Analogue of the FXIIIa Inhibitor Tridegin: New Insights into Structure–Activity Relationships

2021 ◽  
Vol 22 (2) ◽  
pp. 880
Author(s):  
Thomas Schmitz ◽  
Ajay Abisheck Paul George ◽  
Britta Nubbemeyer ◽  
Charlotte A. Bäuml ◽  
Torsten Steinmetzer ◽  
...  
Keyword(s):  
Structural Information ◽  
Coagulation Factor ◽  
Md Simulations ◽  
2D Nmr ◽  
Label Free ◽  
2D Nmr Spectroscopy ◽  
Structure Information ◽  
Structure Activity Relationships ◽  
Structure Activity ◽  
Blood Sucking

The saliva of blood-sucking leeches contains a plethora of anticoagulant substances. One of these compounds derived from Haementeria ghilianii, the 66mer three-disulfide-bonded peptide tridegin, specifically inhibits the blood coagulation factor FXIIIa. Tridegin represents a potential tool for antithrombotic and thrombolytic therapy. We recently synthesized two-disulfide-bonded tridegin variants, which retained their inhibitory potential. For further lead optimization, however, structure information is required. We thus analyzed the structure of a two-disulfide-bonded tridegin isomer by solution 2D NMR spectroscopy in a combinatory approach with subsequent MD simulations. The isomer was studied using two fragments, i.e., the disulfide-bonded N-terminal (Lys1–Cys37) and the flexible C-terminal part (Arg38–Glu66), which allowed for a simplified, label-free NMR-structure elucidation of the 66mer peptide. The structural information was subsequently used in molecular modeling and docking studies to provide insights into the structure–activity relationships. The present study will prospectively support the development of anticoagulant-therapy-relevant compounds targeting FXIIIa.

scholarly journals Correction to Plasmon-Enhanced Autofluorescence Imaging of Organelles in Label-Free Cells by Deep-Ultraviolet Excitation

2016 ◽  
Vol 88 (8) ◽  
pp. 4580-4580
Author(s):  
Masakazu Kikawada ◽  
Atsushi Ono ◽  
Wataru Inami ◽  
Yoshimasa Kawata
Keyword(s):  
Autofluorescence Imaging ◽  
Label Free ◽  
Ultraviolet Excitation ◽  
Free Cells ◽  
Deep Ultraviolet

One-Dimensional Diffraction Grating of Poly(Methacrylic Acid) Brushes For The Rapid Label-Free Detection of Yersinia Pestis With a Reflective Laser System

2021 ◽  
Author(s):  
Feng-Ping Lin ◽  
Hui-Ling Hsu ◽  
Hui-Chung Lin ◽  
Hsin-Hsien Huang ◽  
Chien-Hsing Lu ◽  
...  
Keyword(s):  
Laser Beam ◽  
Yersinia Pestis ◽  
Methacrylic Acid ◽  
Limit Of Detection ◽  
Incident Angle ◽  
Diffraction Effect ◽  
Label Free ◽  
Diffraction Intensity ◽  
One Dimensional ◽  
Label Free Detection

Abstract Background: Because of the low sensitivity of commercial products, development of a facile method to rapidly identify plague on-site remains highly attractive. Line arrays of poly(methacrylic acid) (PMAA) brushes were grafted using a photoresist template to fabricate one-dimensional diffraction gratings (DGs). The as-prepared samples first bound protein G to immobilize and orient the tails of the antibody of Yersinia pestis (abY). A laser beam was employed to analyze the 2D and 3D reflective signals of DGs at an incident angle of 45°. The abY-tailed PMAA DG possessed an optical feature with a characteristic diffraction effect along the SII, in which the projection of the laser beam on the plane of the DG chip was parallel to the strips, and ST configurations, in which they were perpendicular. A fluidic diffraction chip based on the abY-tailed PMMA DG was fabricated to examine the ability to detect Yersinia pestis along the ST configuration. Results: Upon flowing through the chip, Yersinia pestis was attached to the abY-tailed PMMA DG, which changed the diffraction intensity. The degree of the diffraction intensity exhibited a linear response to Yersinia pestis at concentrations from 102 to 107 CFU mL−1, and the limit of detection was 75 CFU mL−1, 1000 times lower than a commercial product (Alexter Bio-Detect Test). The diffractive sensor could selectively detect Yersinia pestis in spiked serum samples, with excellent standard deviation and recovery. Conclusion: Our platform provides a simple, label-free method for on-site plague diagnosis to prevent the highly rapid transmission of plague.

scholarly journals Plasmonic nanocrystals on polycarbonate substrates for direct and label-free biodetection of Interleukin-6 in bioengineered 3D skeletal muscles

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Gerardo A Lopez-Muñoz ◽  
Juan M Fernández-Costa ◽  
Maria Alejandra Ortega ◽  
Jordina Balaguer-Trias ◽  
Eduard Martin-Lasierra ◽  
...  
Keyword(s):  
Interleukin 6 ◽  
Limit Of Detection ◽  
Culture Media ◽  
Incident Angle ◽  
Wide Field ◽  
Label Free ◽  
Cell Culture Media ◽  
Muscle Tissues ◽  
Label Free Detection ◽  
Potential Benefits

Abstract The development of nanostructured plasmonic biosensors has been widely widespread in the last years, motivated by the potential benefits they can offer in integration, miniaturization, multiplexing opportunities, and enhanced performance label-free biodetection in a wide field of applications. Between them, engineering tissues represent a novel, challenging, and prolific application field for nanostructured plasmonic biosensors considering the previously described benefits and the low levels of secreted biomarkers (≈pM–nM) to detect. Here, we present an integrated plasmonic nanocrystals-based biosensor using high throughput nanostructured polycarbonate substrates. Metallic film thickness and incident angle of light for reflectance measurements were optimized to enhance the detection of antibody–antigen biorecognition events using numerical simulations. We achieved an enhancement in biodetection up to 3× as the incident angle of light decreases, which can be related to shorter evanescent decay lengths. We achieved a high reproducibility between channels with a coefficient of variation below 2% in bulk refractive index measurements, demonstrating a high potential for multiplexed sensing. Finally, biosensing potential was demonstrated by the direct and label-free detection of interleukin-6 biomarker in undiluted cell culture media supernatants from bioengineered 3D skeletal muscle tissues stimulated with different concentrations of endotoxins achieving a limit of detection (LOD) of ≈ 0.03 ng/mL (1.4 pM).

scholarly journals Scalable mapping of myelin and neuron density in the human brain with micrometer resolution

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Shuaibin Chang ◽  
Divya Varadarajan ◽  
Jiarui Yang ◽  
Ichun Anderson Chen ◽  
Sreekanth Kura ◽  
...  
Keyword(s):  
Human Brain ◽  
Neuronal Cell ◽  
Mie Scattering ◽  
Scattering Coefficient ◽  
Neuronal Cell Body ◽  
Label Free ◽  
Neuron Density ◽  
Tissue Scattering ◽  
Mie Scattering Theory ◽  
Strong Linear Relationship

AbstractOptical coherence tomography (OCT) is an emerging 3D imaging technique that allows quantification of intrinsic optical properties such as scattering coefficient and back-scattering coefficient, and has proved useful in distinguishing delicate microstructures in the human brain. The origins of scattering in brain tissues are contributed by the myelin content, neuron size and density primarily; however, no quantitative relationships between them have been reported, which hampers the use of OCT in fundamental studies of architectonic areas in the human brain and the pathological evaluations of diseases. Here, we built a generalized linear model based on Mie scattering theory that quantitatively links tissue scattering to myelin content and neuron density in the human brain. We report a strong linear relationship between scattering coefficient and the myelin content that is retained across different regions of the brain. Neuronal cell body turns out to be a secondary contribution to the overall scattering. The optical property of OCT provides a label-free solution for quantifying volumetric myelin content and neuron cells in the human brain.

2D Label Free Microscopy Imaging Analysis Using Machine Learning

2020 ◽  
Vol 2020 (14) ◽  
pp. 341-1-341-10
Author(s):  
Han Hu ◽  
Yang Lei ◽  
Daisy Xin ◽  
Viktor Shkolnikov ◽  
Steven Barcelo ◽  
...  
Keyword(s):  
Machine Learning ◽  
Free Cell ◽  
Living Cells ◽  
Training Data ◽  
Learning Approaches ◽  
Label Free ◽  
Imaging Analysis ◽  
Microscopy Imaging ◽  
Limited Availability ◽  
Free Cells

Separation and isolation of living cells plays an important role in the fields of medicine and biology with label-free imaging often used for isolating cells. The analysis of label-free cell images has many challenges when examining the behavior of cells. This paper presents methods to analyze label-free cells. Many of the tools we describe are based on machine learning approaches. We also investigate ways of augmenting limited availability of training data. Our results demonstrate that our proposed methods are capable of successfully segmenting and classifying label-free cells.

Proteome-wide biomarker quantification and target screening.

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e15205-e15205
Author(s):  
Qimin Quan ◽  
John Geanacopoulos ◽  
Joshua Ritchey ◽  
Mark Clenow ◽  
Joe Wilkinson ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Single Molecule ◽  
Dynamic Range ◽  
Color Change ◽  
Label Free ◽  
Development Programs ◽  
Color Changes ◽  
Scattering Spectrum ◽  
Proteome Level ◽  
Target Screening

e15205 Background: Existing drug development programs are represented by only a few hundred protein targets. A large subset of the ~20,000 proteins encoded by the human genome remain undiscovered. Proteome-wide “druggability” screening may lead to new targets for therapeutics. Methods: The NanoMosaic platform is a digital immunoassay technology that achieves sub-pg/ml level sensitivity, whole-proteome level multiplexing capability, and 7 logs of dynamic range. The platform overcomes the sensitivity and dynamic range limitations of traditional protein arrays and mass spectrometry. Results: The NanoMosaic technology is powered by silicon nanoneedle biosensors that are densely integrated on a plate and manufactured with CMOS-compatible nanofabrication processes. Each nanoneedle is a label-free biosensor, functionalized with capture antibodies. Its scattering spectrum changes when an antigen binds to its surface. Each analyte specific sensing area consists a total of ~23k nanoneedles divided into a digital region (~20k nanoneedles) and an analog region (~3k nanoneedles). The digital nanoneedles provide the single molecule sensitivity. Therefore, at ultra-low concentration when antigens that are captured by the nanoneedles follow Poisson statistics, the number of antigens can be quantitated by counting the presence or absence of color changes of individual nanoneedles in a binary fashion. As the protein concentrations increase, the binding event counts increase accordingly and achieve saturation when all nanoneedles capture more than one protein. Above the digital saturation concentration, an adjacent section of analog nanoneedles perform quantitative analysis based on the level of color change, thus providing a wider dynamic range up to 1ug/ml. Ultrahigh level multiplex can be achieved by parallelizing the detection in a microarray format without loss of the sensitivity and dynamic range. A 20,000-plex proteome-wide study can be achieved with a total of 5 billion nanoneedles on a ~70mm by 70mm chip. Conclusions: In conclusion, proteome-wide biomarker quantification and target discovery can be performed on the NanoMosaic platform at higher sensitivity, wider dynamic range, lower cost and higher throughput than is currently possible by mass spectrometry or traditional immunoassays.

scholarly journals Label-Free Biosensing Method for the Detection of a Pancreatic Cancer Biomarker Based on Dielectrophoresis Spectroscopy

Chemosensors ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 33 ◽  
Author(s):  
Fleming Dackson Gudagunti ◽  
Logeeshan Velmanickam ◽  
Dharmakeerthi Nawarathna ◽  
Ivan Lima
Keyword(s):  
Pancreatic Cancer ◽  
Early Stage ◽  
Mie Scattering ◽  
Processing Technique ◽  
Cancer Biomarker ◽  
Image Processing Technique ◽  
Label Free ◽  
Transduction Mechanism ◽  
Diagnosis And Prognosis ◽  
Cutoff Levels

We show that negative dielectrophoresis (DEP) spectroscopy is an effective transduction mechanism of a biosensor for the diagnosis and prognosis of pancreatic cancer using the biomarker CA 19-9. A substantial change in the negative DEP force applied to functionalized polystyrene microspheres (PM) was observed with respect to both the concentration level of the pancreatic cancer biomarker CA 19-9 and the frequency of the electric field produced by a pearl shaped interdigitated gold micro-electrode. The velocity of repulsion of a set of PM functionalized to a monoclonal antibody to CA 19-9 was calculated for several concentration cutoff levels of CA 19-9, including 0 U/mL and 37 U/mL, at the frequency range from 0.5 to 2 MHz. The velocity of repulsion of the PM from the electrode was determined using a side illumination and an automated software using a real-time image processing technique that captures the Mie scattering from the PM. Since negative DEP spectroscopy is an effective transduction mechanism for the detection of the cutoff levels of CA 19-9, it has the potential to be used in the early stage diagnosis and in the prognosis of pancreatic cancer.

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