1
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Ho RJ, Yeh K, Liu YT, Bhargava R. Sensitive Discrete Frequency Mid-Infrared Absorption Spectroscopy Using Digitally Referenced Detection. Anal Chem 2024; 96:8990-8998. [PMID: 38771296 DOI: 10.1021/acs.analchem.4c00134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Broadly tunable mid-infrared (IR) lasers, including quantum cascade lasers (QCL), are an asset for vibrational spectroscopy wherein high-intensity, coherent illumination can target specific spectral bands for rapid, direct chemical detection with microscopic localization. These emerging spectrometers are capable of high measurement throughputs with large detector signals from the high-intensity lasers and fast detection speeds as short as a single laser pulse, challenging the decades old benchmarks of Fourier transform infrared spectroscopy. However, noise in QCL emissions limits the feasible acquisition time for high signal-to-noise ratio (SNR) data. Here, we present an implementation that is broadly compatible with many laser-based spectrometer and microscope designs to address these limitations by leveraging high-speed digitizers and dual detectors to digitally reference each pulse individually. Digitally referenced detection (DRD) is shown to improve measurement sensitivity, with broad spectral indifference, regardless of imbalance due to dissimilarities among system designs or component manufacturers. We incorporated DRD into existing instruments and demonstrated its generalizability: a spectrometer with a 10-fold reduction in spectral noise, a microscope with reduced pixel dwell times to as low as 1 pulse while maintaining SNR normally achieved when operating 8-fold slower, and finally, a spectrometer to measure vibrational circular dichroism (VCD) with a ∼ 4-fold reduction in scan times. The approach not only proves versatile and effective but can also be tailored for specific applications with minimal hardware changes, positioning it as a simple and promising module for spectrometer designs using lasers.
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Affiliation(s)
- Ruo-Jing Ho
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Kevin Yeh
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Yen-Ting Liu
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Rohit Bhargava
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Department of Chemical and Biomolecular Engineering, Department of Chemistry, Department of Mechanical Science and Engineering, and Cancer Center at Illinois, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
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2
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Takahashi S, Oguchi K, Kamei K, Mizuguchi T, Spratt SJ, Ozeki Y. Widely tunable fiber optical parametric oscillator synchronized with a Ti:sapphire laser for stimulated Raman scattering microscopy. BIOMEDICAL OPTICS EXPRESS 2024; 15:3191-3199. [PMID: 38855684 PMCID: PMC11161345 DOI: 10.1364/boe.515446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 03/29/2024] [Accepted: 04/09/2024] [Indexed: 06/11/2024]
Abstract
Stimulated Raman scattering (SRS) microscopy is a powerful vibrational imaging technique with high chemical specificity. However, the insufficient tuning range or speed of light sources limits the spectral range of SRS imaging and, hence, the ability to identify molecular species. Here, we present a widely tunable fiber optical parametric oscillator with a tuning range of 1470 cm-1, which can be synchronized with a Ti:sapphire laser. By using the synchronized light sources, we develop an SRS imaging system that covers the fingerprint and C-H stretching regions, without balanced detection. We validate its broadband imaging capability by visualizing a mixed polymer sample in multiple vibrational modes. We also demonstrate SRS imaging of HeLa cells, showing the applicability of our SRS microscope to biological samples.
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Affiliation(s)
- Shun Takahashi
- Department of Electrical Engineering and Information Systems, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Kenichi Oguchi
- Research Center for Advanced Science and Technology, The University of Tokyo, Meguro-ku, Tokyo 153-8904, Japan
| | - Kento Kamei
- Department of Electrical and Electronic Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Takaha Mizuguchi
- Research Center for Advanced Science and Technology, The University of Tokyo, Meguro-ku, Tokyo 153-8904, Japan
| | - Spencer J. Spratt
- Research Center for Advanced Science and Technology, The University of Tokyo, Meguro-ku, Tokyo 153-8904, Japan
| | - Yasuyuki Ozeki
- Department of Electrical Engineering and Information Systems, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
- Research Center for Advanced Science and Technology, The University of Tokyo, Meguro-ku, Tokyo 153-8904, Japan
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3
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Wang M, Huang Z, Wu C, Yan S, Fang HT, Pan W, Tan QG, Pan K, Ji R, Yang L, Pan B, Wang P, Miao AJ. Stimulated Raman Scattering Microscopy Reveals Bioaccumulation of Small Microplastics in Protozoa from Natural Waters. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:2922-2930. [PMID: 38294405 DOI: 10.1021/acs.est.3c07486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
Microplastics (MPs) are pollutants of global concern, and bioaccumulation determines their biological effects. Although microorganisms form a large fraction of our ecosystem's biomass and are important in biogeochemical cycling, their accumulation of MPs has never been confirmed in natural waters because current tools for field biological samples can detect only MPs > 10 μm. Here, we show that stimulated Raman scattering microscopy (SRS) can image and quantify the bioaccumulation of small MPs (<10 μm) in protozoa. Our label-free method, which differentiates MPs by their SRS spectra, detects individual and mixtures of different MPs (e.g., polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, polystyrene, and poly(methyl methacrylate)) in protozoa. The ability of SRS to quantify cellular MP accumulation is similar to that of flow cytometry, a fluorescence-based method commonly used to determine cellular MP accumulation. Moreover, we discovered that protozoa in water samples from Yangtze River, Xianlin Wastewater Treatment Plant, Lake Taihu and the Pearl River Estuary accumulated MPs < 10 μm, but the proportion of MP-containing cells was low (∼2-5%). Our findings suggest that small MPs could potentially enter the food chain and transfer to organisms at higher trophic levels, posing environmental and health risks that deserve closer scrutiny.
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Affiliation(s)
- Mei Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu Province 210023, China PRC
| | - Zhiliang Huang
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, Hubei Province 430074, China PRC
| | - Chao Wu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu Province 210023, China PRC
| | - Shuai Yan
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, Hubei Province 430074, China PRC
| | - Hai-Tao Fang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu Province 210023, China PRC
| | - Wei Pan
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu Province 210023, China PRC
| | - Qiao-Guo Tan
- Key Laboratory of the Coastal and Wetland Ecosystems of Ministry of Education, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian 361102, China PRC
| | - Ke Pan
- Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China PRC
| | - Rong Ji
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu Province 210023, China PRC
| | - Liuyan Yang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu Province 210023, China PRC
| | - Bingcai Pan
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu Province 210023, China PRC
| | - Ping Wang
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, Hubei Province 430074, China PRC
| | - Ai-Jun Miao
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu Province 210023, China PRC
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4
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Ni H, Dessai CP, Lin H, Wang W, Chen S, Yuan Y, Ge X, Ao J, Vild N, Cheng JX. High-content stimulated Raman histology of human breast cancer. Theranostics 2024; 14:1361-1370. [PMID: 38389847 PMCID: PMC10879861 DOI: 10.7150/thno.90336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 12/17/2023] [Indexed: 02/24/2024] Open
Abstract
Histological examination is crucial for cancer diagnosis, however, the labor-intensive sample preparation involved in the histology impedes the speed of diagnosis. Recently developed two-color stimulated Raman histology could bypass the complex tissue processing to generates result close to hematoxylin and eosin staining, which is one of the golden standards in cancer histology. Yet, the underlying chemical features are not revealed in two-color stimulated Raman histology, compromising the effectiveness of prognostic stratification. Here, we present a high-content stimulated Raman histology (HC-SRH) platform that provides both morphological and chemical information for cancer diagnosis based on un-stained breast tissues. Methods: By utilizing both hyperspectral SRS imaging in the C-H vibration window and sparsity-penalized unmixing of overlapped spectral profiles, HC-SRH enabled high-content chemical mapping of saturated lipids, unsaturated lipids, cellular protein, extracellular matrix (ECM), and water. Spectral selective sampling was further implemented to boost the speed of HC-SRH. To show the potential for clinical use, HC-SRH using a compact fiber laser-based stimulated Raman microscope was demonstrated. Harnessing the wide and rapid tuning capability of the fiber laser, both C-H and fingerprint vibration windows were accessed. Results: HC-SRH successfully mapped unsaturated lipids, cellular protein, extracellular matrix, saturated lipid, and water in breast tissue. With these five chemical maps, HC-SRH provided distinct contrast for tissue components including duct, stroma, fat cell, necrosis, and vessel. With selective spectral sampling, the speed of HC-SRH was improved by one order of magnitude. The fiber-laser-based HC-SRH produced the same image quality in the C-H window as the state-of-the-art solid laser. In the fingerprint window, nucleic acid and solid-state ester contrast was demonstrated. Conclusions: HC-SRH provides both morphological and chemical information of tissue in a label-free manner. The chemical information detected is beyond the reach of traditional hematoxylin and eosin staining and heralds the potential of HC-SRH for biomarker discovery.
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Affiliation(s)
- Hongli Ni
- Department of Electrical and Computer Engineering, Boston University, 8 St. Mary's St., Boston, MA, 02215, USA
| | | | - Haonan Lin
- Department of Electrical and Computer Engineering, Boston University, 8 St. Mary's St., Boston, MA, 02215, USA
| | - Wei Wang
- Hologic Inc., 250 campus drive, Marlborough, MA 01752, USA
| | - Shaoxiong Chen
- Indiana University School of Medicine 340 West 10th Street, Fairbanks Hall, Suite 6200, IN 46202, USA
| | - Yuhao Yuan
- Department of Electrical and Computer Engineering, Boston University, 8 St. Mary's St., Boston, MA, 02215, USA
| | - Xiaowei Ge
- Department of Electrical and Computer Engineering, Boston University, 8 St. Mary's St., Boston, MA, 02215, USA
| | - Jianpeng Ao
- Department of Electrical and Computer Engineering, Boston University, 8 St. Mary's St., Boston, MA, 02215, USA
| | - Nolan Vild
- Department of Electrical and Computer Engineering, Boston University, 8 St. Mary's St., Boston, MA, 02215, USA
| | - Ji-Xin Cheng
- Department of Electrical and Computer Engineering, Boston University, 8 St. Mary's St., Boston, MA, 02215, USA
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, MA 02215, USA
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5
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Corso C, Mansuryan T, Tonello A, Arosa Y, Stepanenko Y, Couderc V, Krupa K. Tunable four-wave mixing enabled by a self-phase modulation of chirped pulses. OPTICS LETTERS 2023; 48:5531-5534. [PMID: 37910695 DOI: 10.1364/ol.502065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 09/29/2023] [Indexed: 11/03/2023]
Abstract
We experimentally demonstrate how a concatenation of the standard and microstructure fiber segments permits adjusting the four-wave mixing sideband position over a large spectral range by varying the chirp of an input pulsed pump at a fixed wavelength in the presence of a self-phase modulation. The blue- and redshifted sidebands can stand aside over ∼200 nm and ∼450 nm from the pump, respectively, which agrees well with the numerical simulations. We validate our approach by showing the feasibility of CARS imaging.
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6
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Jiang Z, Wang X, Chu K, Smith ZJ. Fast Raman imaging through the combination of context-aware matrix completion and low spectral resolution. Analyst 2023; 148:4710-4720. [PMID: 37622207 DOI: 10.1039/d3an00997a] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/26/2023]
Abstract
Raman hyperspectral imaging is an effective method for label-free imaging with chemical specificity, yet the weak signals and correspondingly long integration times have hindered its wide adoption as a routine analytical method. Recently, low resolution Raman imaging has been proposed to improve the spectral signal-to-noise ratio, which significantly improves the speed of Raman imaging. In this paper, low resolution Raman spectroscopy is combined with "context-aware" matrix completion, where regions of the sample that are not of interest are skipped, and the regions that are measured are under-sampled, then reconstructed with a low-rank constraint. Both simulations and experiment show that low-resolution Raman boosts the speed and image quality of the computationally-reconstructed Raman images, allowing deeper sub-sampling, reduced exposure time, and an overall >10-fold improvement in imaging speed, without sacrificing chemical specificity or spatial image quality. As the method utilizes traditional point-scan imaging, it retains full confocality and is "backwards-compatible" with pre-existing traditional Raman instruments, broadening the potential scope of Raman imaging applications.
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Affiliation(s)
- Ziling Jiang
- University of Science and Technology of China, Department of Precision Machinery & Precision Instrumentation, Hefei, Anhui, China 230027.
| | - Xianli Wang
- University of Science and Technology of China, Department of Precision Machinery & Precision Instrumentation, Hefei, Anhui, China 230027.
| | - Kaiqin Chu
- University of Science and Technology of China, Suzhou Institute for Advanced Research, Suzhou, Jiangsu, China 215123
| | - Zachary J Smith
- University of Science and Technology of China, Department of Precision Machinery & Precision Instrumentation, Hefei, Anhui, China 230027.
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7
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Tan Y, Lin H, Cheng JX. Profiling single cancer cell metabolism via high-content SRS imaging with chemical sparsity. SCIENCE ADVANCES 2023; 9:eadg6061. [PMID: 37585522 PMCID: PMC10431717 DOI: 10.1126/sciadv.adg6061] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 07/14/2023] [Indexed: 08/18/2023]
Abstract
Metabolic reprogramming in a subpopulation of cancer cells is a hallmark of tumor chemoresistance. However, single-cell metabolic profiling is difficult because of the lack of a method that can simultaneously detect multiple metabolites at the single-cell level. In this study, through hyperspectral stimulated Raman scattering (hSRS) imaging in the carbon-hydrogen (C-H) window and sparsity-driven hyperspectral image decomposition, we demonstrate a high-content hSRS (h2SRS) imaging approach that enables the simultaneous mapping of five major biomolecules, including proteins, carbohydrates, fatty acids, cholesterol, and nucleic acids at the single-cell level. h2SRS imaging of brain and pancreatic cancer cells under chemotherapy revealed acute and adapted chemotherapy-induced metabolic reprogramming and the unique metabolic features of chemoresistance. Our approach is expected to facilitate the discovery of therapeutic targets to combat chemoresistance. This study illustrates a high-content, label-free chemical imaging approach that measures metabolic profiles at the single-cell level and warrants further research on cellular metabolism.
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Affiliation(s)
- Yuying Tan
- Biomedical Engineering, Boston University, Boston, MA 02155, USA
| | - Haonan Lin
- Biomedical Engineering, Boston University, Boston, MA 02155, USA
| | - Ji-Xin Cheng
- Biomedical Engineering, Boston University, Boston, MA 02155, USA
- Electrical and Computer Engineering, Boston University, Boston, MA 02155, USA
- Photonics Center, Boston University, Boston, MA 02155, USA
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8
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Pastorczak M, Duk K, Shahab S, Kananenka AA. Combinational Vibration Modes in H 2O/HDO/D 2O Mixtures Detected Thanks to the Superior Sensitivity of Femtosecond Stimulated Raman Scattering. J Phys Chem B 2023. [PMID: 37201478 DOI: 10.1021/acs.jpcb.3c01334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Overtones and combinational modes frequently play essential roles in ultrafast vibrational energy relaxation in liquid water. However, these modes are very weak and often overlap with fundamental modes, particularly in isotopologues mixtures. We measured VV and HV Raman spectra of H2O and D2O mixtures with femtosecond stimulated Raman scattering (FSRS) and compared the results with calculated spectra. Specifically, we observed the mode at around 1850 cm-1 and assigned it to H-O-D bend + rocking libration. Second, we found that the H-O-D bend overtone band and the OD stretch + rocking libration combination band contribute to the band located between 2850 and 3050 cm-1. Furthermore, we assigned the broad band located between 4000 and 4200 cm-1 to be composed of combinational modes of high-frequency OH stretching modes with predominantly twisting and rocking librations. These results should help in a proper interpretation of Raman spectra of aqueous systems as well as in the identification of vibrational relaxation pathways in isotopically diluted water.
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Affiliation(s)
- Marcin Pastorczak
- Institute of Physical Chemistry, Polish Academy of Sciences, Laser Centre, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Katsiaryna Duk
- Institute of Physical Chemistry, Polish Academy of Sciences, Laser Centre, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Samaneh Shahab
- Institute of Physical Chemistry, Polish Academy of Sciences, Laser Centre, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Alexei A Kananenka
- Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, United States
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9
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Xu FX, Rathbone EG, Fu D. Simultaneous Dual-Band Hyperspectral Stimulated Raman Scattering Microscopy with Femtosecond Optical Parametric Oscillators. J Phys Chem B 2023; 127:2187-2197. [PMID: 36883604 PMCID: PMC10144064 DOI: 10.1021/acs.jpcb.2c09105] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023]
Abstract
Stimulated Raman scattering (SRS) microscopy is a label-free quantitative optical technique for imaging molecular distributions in cells and tissues by probing their intrinsic vibrational frequencies. Despite its usefulness, existing SRS imaging techniques have limited spectral coverage due to either a wavelength tuning constraint or narrow spectral bandwidth. High-wavenumber SRS imaging is commonly used to map lipid and protein distribution in biological cells and visualize cell morphology. However, to detect small molecules or Raman tags, imaging in the fingerprint region or "silent" region, respectively, is often required. For many applications, it is desirable to collect SRS images in two Raman spectral regions simultaneously for visualizing the distribution of specific molecules in cellular compartments or providing accurate ratiometric analysis. In this work, we present an SRS microscopy system using three beams generated by a femtosecond oscillator to acquire hyperspectral SRS image stacks in two arbitrary vibrational frequency bands, between 650-3280 cm-1, simultaneously. We demonstrate potential biomedical applications of the system in investigating fatty acid metabolism, cellular drug uptake and accumulation, and lipid unsaturation level in tissues. We also show that the dual-band hyperspectral SRS imaging system can be adapted for the broadband fingerprint region hyperspectral imaging (1100-1800 cm-1) by simply adding a modulator.
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Affiliation(s)
- Fiona Xi Xu
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Emily G Rathbone
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Dan Fu
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
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10
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Zhang J, Shin J, Tague N, Lin H, Zhang M, Ge X, Wong W, Dunlop MJ, Cheng J. Visualization of a Limonene Synthesis Metabolon Inside Living Bacteria by Hyperspectral SRS Microscopy. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2203887. [PMID: 36169112 PMCID: PMC9661820 DOI: 10.1002/advs.202203887] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 08/21/2022] [Indexed: 06/16/2023]
Abstract
Monitoring biosynthesis activity at single-cell level is key to metabolic engineering but is still difficult to achieve in a label-free manner. Using hyperspectral stimulated Raman scattering imaging in the 670-900 cm-1 region, localized limonene synthesis are visualized inside engineered Escherichia coli. The colocalization of limonene and GFP-fused limonene synthase is confirmed by co-registered stimulated Raman scattering and two-photon fluorescence images. The finding suggests a limonene synthesis metabolon with a polar distribution inside the cells. This finding expands the knowledge of de novo limonene biosynthesis in engineered bacteria and highlights the potential of SRS chemical imaging in metabolic engineering research.
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Affiliation(s)
- Jing Zhang
- Department of Biomedical EngineeringBoston UniversityBostonMA02215USA
- Photonics CenterBoston UniversityBostonMA02215USA
| | - Jonghyeon Shin
- Department of Biomedical EngineeringBoston UniversityBostonMA02215USA
| | - Nathan Tague
- Department of Biomedical EngineeringBoston UniversityBostonMA02215USA
- Biological Design CenterBoston UniversityBostonMA02215USA
| | - Haonan Lin
- Department of Biomedical EngineeringBoston UniversityBostonMA02215USA
- Photonics CenterBoston UniversityBostonMA02215USA
| | - Meng Zhang
- Photonics CenterBoston UniversityBostonMA02215USA
- Department of Electrical and Computer EngineeringBoston UniversityBostonMA02215USA
| | - Xiaowei Ge
- Photonics CenterBoston UniversityBostonMA02215USA
- Department of Electrical and Computer EngineeringBoston UniversityBostonMA02215USA
| | - Wilson Wong
- Department of Biomedical EngineeringBoston UniversityBostonMA02215USA
- Biological Design CenterBoston UniversityBostonMA02215USA
| | - Mary J. Dunlop
- Department of Biomedical EngineeringBoston UniversityBostonMA02215USA
- Biological Design CenterBoston UniversityBostonMA02215USA
| | - Ji‐Xin Cheng
- Department of Biomedical EngineeringBoston UniversityBostonMA02215USA
- Photonics CenterBoston UniversityBostonMA02215USA
- Department of Electrical and Computer EngineeringBoston UniversityBostonMA02215USA
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11
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Hislop EW, Tipping WJ, Faulds K, Graham D. Label-Free Imaging of Lipid Droplets in Prostate Cells Using Stimulated Raman Scattering Microscopy and Multivariate Analysis. Anal Chem 2022; 94:8899-8908. [PMID: 35699644 PMCID: PMC9244870 DOI: 10.1021/acs.analchem.2c00236] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
Hyperspectral stimulated
Raman scattering (SRS) microscopy is a
powerful imaging modality for the analysis of biological systems.
Here, we report the application of k-means cluster
analysis (KMCA) of multi-wavelength SRS images in the high-wavenumber
region of the Raman spectrum as a robust and reliable method for the
segmentation of cellular organelles based on the intrinsic SRS spectrum.
KMCA has been applied to the study of the endogenous lipid biochemistry
of prostate cancer and prostate healthy cell models, while the corresponding
SRS spectrum of the lipid droplet (LD) cluster enabled direct comparison
of their composition. The application of KMCA in visualizing the LD
content of prostate cell models following the inhibition of de novo
lipid synthesis (DNL) using the acetyl-coA carboxylase inhibitor,
5-(tetradecyloxy)-2-furoic acid (TOFA), is demonstrated. This method
identified a reliance of prostate cancer cell models upon DNL for
metabolic requirements, with a significant reduction in the cellular
LD content after treatment with TOFA, which was not observed in normal
prostate cell models. SRS imaging combined with KMCA is a robust method
for investigating drug–cell interactions in a label-free manner.
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Affiliation(s)
- Ewan W Hislop
- Centre for Molecular Nanometrology, WestCHEM, Department of Pure and Applied Chemistry, Technology and Innovation Centre, University of Strathclyde, Glasgow G1 1RD, U.K
| | - William J Tipping
- Centre for Molecular Nanometrology, WestCHEM, Department of Pure and Applied Chemistry, Technology and Innovation Centre, University of Strathclyde, Glasgow G1 1RD, U.K
| | - Karen Faulds
- Centre for Molecular Nanometrology, WestCHEM, Department of Pure and Applied Chemistry, Technology and Innovation Centre, University of Strathclyde, Glasgow G1 1RD, U.K
| | - Duncan Graham
- Centre for Molecular Nanometrology, WestCHEM, Department of Pure and Applied Chemistry, Technology and Innovation Centre, University of Strathclyde, Glasgow G1 1RD, U.K
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