High-speed hyperspectral Raman imaging for label-free compositional microanalysis

Lateral Flow Immunoassays (LFIAs) allow for rapid, low-cost, screening of many biomolecules such as food allergens. Despite being classified as rapid tests, many LFIAs take 10–20 min to complete. For a really high-speed LFIA, it is necessary to assess antibody association kinetics. By using a label-free optical technique such as Surface Plasmon Resonance (SPR), it is possible to screen crude monoclonal antibody (mAb) preparations for their association rates against a target. Herein, we describe an SPR-based method for screening and selecting crude anti-hazelnut antibodies based on their relative association rates, cross reactivity and sandwich pairing capabilities, for subsequent application in a rapid ligand binding assay. Thanks to the SPR selection process, only the fast mAb (F-50-6B12) and the slow (S-50-5H9) mAb needed purification for labelling with carbon nanoparticles to exploit high-speed LFIA prototypes. The kinetics observed in SPR were reflected in LFIA, with the test line appearing within 30 s, almost two times faster when F-50-6B12 was used, compared with S-50-5H9. Additionally, the LFIAs have demonstrated their future applicability to real life samples by detecting hazelnut in the sub-ppm range in a cookie matrix. Finally, these LFIAs not only provide a qualitative result when read visually, but also generate semi-quantitative data when exploiting freely downloadable smartphone apps.

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High-Speed Label-Free Spectroscopic Biological Imaging Based on Stimulated Raman Scattering MicroscopyHigh-Speed Label-Free Spectroscopic Biological Imaging Based on Stimulated Raman Scattering MicroscopyHigh-Speed Label-Free Spectroscopic Biological Imaging Based on Stimulated Raman Scattering Microscopy

The Review of Laser Engineering ◽

10.2184/lsj.45.6_328 ◽

2017 ◽

Vol 45 (6) ◽

pp. 328

Author(s):

Yasuyuki OZEKI

Keyword(s):

Raman Scattering ◽

High Speed ◽

Stimulated Raman Scattering ◽

Biological Imaging ◽

Label Free ◽

Stimulated Raman

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High-speed label-free ultraviolet photoacoustic microscopy for medical applications

10.14711/thesis-991012879765903412 ◽

2020 ◽

Author(s):

Xiufeng Li

Keyword(s):

High Speed ◽

Medical Applications ◽

Photoacoustic Microscopy ◽

Label Free

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Label-free vibrational imaging of different Aβ plaque types in Alzheimer’s disease reveals sequential events in plaque development

Acta Neuropathologica Communications ◽

10.1186/s40478-020-01091-5 ◽

2020 ◽

Vol 8 (1) ◽

Author(s):

Dominik Röhr ◽

Baayla D. C. Boon ◽

Martin Schuler ◽

Kristin Kremer ◽

Jeroen J. M. Hoozemans ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Brain Tissue ◽

Raman Imaging ◽

Label Free ◽

Human Brain Tissue ◽

Plaque Development ◽

Β Sheets ◽

Diffuse Plaques ◽

Insight Into

AbstractThe neuropathology of Alzheimer’s disease (AD) is characterized by hyperphosphorylated tau neurofibrillary tangles (NFTs) and amyloid-beta (Aβ) plaques. Aβ plaques are hypothesized to follow a development sequence starting with diffuse plaques, which evolve into more compact plaques and finally mature into the classic cored plaque type. A better molecular understanding of Aβ pathology is crucial, as the role of Aβ plaques in AD pathogenesis is under debate. Here, we studied the deposition and fibrillation of Aβ in different plaque types with label-free infrared and Raman imaging. Fourier-transform infrared (FTIR) and Raman imaging was performed on native snap-frozen brain tissue sections from AD cases and non-demented control cases. Subsequently, the scanned tissue was stained against Aβ and annotated for the different plaque types by an AD neuropathology expert. In total, 160 plaques (68 diffuse, 32 compact, and 60 classic cored plaques) were imaged with FTIR and the results of selected plaques were verified with Raman imaging. In diffuse plaques, we detect evidence of short antiparallel β-sheets, suggesting the presence of Aβ oligomers. Aβ fibrillation significantly increases alongside the proposed plaque development sequence. In classic cored plaques, we spatially resolve cores containing predominantly large parallel β-sheets, indicating Aβ fibrils. Combining label-free vibrational imaging and immunohistochemistry on brain tissue samples of AD and non-demented cases provides novel insight into the spatial distribution of the Aβ conformations in different plaque types. This way, we reconstruct the development process of Aβ plaques in human brain tissue, provide insight into Aβ fibrillation in the brain, and support the plaque development hypothesis.

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Label-free chemical imaging flow cytometry by high-speed multicolor stimulated Raman scattering

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1902322116 ◽

2019 ◽

Vol 116 (32) ◽

pp. 15842-15848 ◽

Cited By ~ 26

Author(s):

Yuta Suzuki ◽

Koya Kobayashi ◽

Yoshifumi Wakisaka ◽

Dinghuan Deng ◽

Shunji Tanaka ◽

...

Keyword(s):

Flow Cytometry ◽

Raman Scattering ◽

Cancer Biology ◽

High Speed ◽

Stimulated Raman Scattering ◽

Chemical Imaging ◽

Fluorescent Labeling ◽

Label Free ◽

Imaging Flow Cytometry ◽

Stimulated Raman

Combining the strength of flow cytometry with fluorescence imaging and digital image analysis, imaging flow cytometry is a powerful tool in diverse fields including cancer biology, immunology, drug discovery, microbiology, and metabolic engineering. It enables measurements and statistical analyses of chemical, structural, and morphological phenotypes of numerous living cells to provide systematic insights into biological processes. However, its utility is constrained by its requirement of fluorescent labeling for phenotyping. Here we present label-free chemical imaging flow cytometry to overcome the issue. It builds on a pulse pair-resolved wavelength-switchable Stokes laser for the fastest-to-date multicolor stimulated Raman scattering (SRS) microscopy of fast-flowing cells on a 3D acoustic focusing microfluidic chip, enabling an unprecedented throughput of up to ∼140 cells/s. To show its broad utility, we use the SRS imaging flow cytometry with the aid of deep learning to study the metabolic heterogeneity of microalgal cells and perform marker-free cancer detection in blood.

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Introduction to Infrared and Raman-Based Biomedical Molecular Imaging and Comparison with Other Modalities

Molecules ◽

10.3390/molecules25235547 ◽

2020 ◽

Vol 25 (23) ◽

pp. 5547

Author(s):

Carlos F. G. C. Geraldes

Keyword(s):

Computed Tomography ◽

Molecular Imaging ◽

Single Photon ◽

Ex Vivo ◽

Photon Emission ◽

Raman Imaging ◽

Emission Computed Tomography ◽

Label Free ◽

Advantages And Disadvantages

Molecular imaging has rapidly developed to answer the need of image contrast in medical diagnostic imaging to go beyond morphological information to include functional differences in imaged tissues at the cellular and molecular levels. Vibrational (infrared (IR) and Raman) imaging has rapidly emerged among the molecular imaging modalities available, due to its label-free combination of high spatial resolution with chemical specificity. This article presents the physical basis of vibrational spectroscopy and imaging, followed by illustration of their preclinical in vitro applications in body fluids and cells, ex vivo tissues and in vivo small animals and ending with a brief discussion of their clinical translation. After comparing the advantages and disadvantages of IR/Raman imaging with the other main modalities, such as magnetic resonance imaging (MRI), computed tomography (CT), positron emission tomography/single-photon emission-computed tomography (PET/SPECT), ultrasound (US) and photoacoustic imaging (PAI), the design of multimodal probes combining vibrational imaging with other modalities is discussed, illustrated by some preclinical proof-of-concept examples.

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Volumetric stimulated Raman imaging with a high-speed deformable mirror (Conference Presentation)

Label-free Biomedical Imaging and Sensing (LBIS) 2019 ◽

10.1117/12.2513208 ◽

2019 ◽

Author(s):

Peng Lin ◽

Hongli Ni ◽

Huate Li ◽

Fengyuan Deng ◽

Nicholas A. Vickers ◽

...

Keyword(s):

High Speed ◽

Raman Imaging ◽

Deformable Mirror ◽

Stimulated Raman

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Labeled vs. Label-Free Raman Imaging of Lipids in Endothelial Cells of Various Origins

Molecules ◽

10.3390/molecules25235752 ◽

2020 ◽

Vol 25 (23) ◽

pp. 5752

Author(s):

Basseem Radwan ◽

Adriana Adamczyk ◽

Szymon Tott ◽

Krzysztof Czamara ◽

Katarzyna Kaminska ◽

...

Keyword(s):

Raman Spectroscopy ◽

Endothelial Cells ◽

Lipid Content ◽

Single Layer ◽

Vascular Diseases ◽

Raman Imaging ◽

Dependent Manner ◽

Label Free ◽

Necrosis Factor Alpha ◽

Cellular Lipids

Endothelial cells (EC) constitute a single layer of the lining of blood vessels and play an important role in maintaining cardiovascular homeostasis. Endothelial dysfunction has been recognized as a primary or secondary cause of many diseases and it manifests itself, among others, by increased lipid content or a change in the lipid composition in the EC. Therefore, the analysis of cellular lipids is crucial to understand the mechanisms of disease development. Tumor necrosis factor alpha (TNF-α)-induced inflammation of EC alters the lipid content of cells, which can be detected by Raman spectroscopy. By default, lipid detection is carried out in a label-free manner, and these compounds are recognized based on their spectral profile characteristics. We consider (3S,3′S)-astaxanthin (AXT), a natural dye with a characteristic resonance spectrum, as a new Raman probe for the detection of lipids in the EC of various vascular beds, i.e., the aorta, brain and heart. AXT colocalizes with lipids in cells, enabling imaging of lipid-rich cellular components in a time-dependent manner using laser power 10 times lower than that commonly used to measure biological samples. The results show that AXT can be used to study lipids distribution in EC at various locations, suggesting its use as a universal probe for studying cellular lipids using Raman spectroscopy. The use of labeled Raman imaging of lipids in the EC of various organs could contribute to their easier identification and to a better understanding of the development and progression of various vascular diseases, and it could also potentially improve their diagnosis and treatment.

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