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Zhang L, Pleskow DK, Turzhitsky V, Yee EU, Berzin TM, Sawhney M, Shinagare S, Vitkin E, Zakharov Y, Khan U, Wang F, Goldsmith JD, Goldberg S, Chuttani R, Itzkan I, Qiu L, Perelman LT. Light scattering spectroscopy identifies the malignant potential of pancreatic cysts during endoscopy. Nat Biomed Eng 2017; 1. [PMID: 29057146 PMCID: PMC5646377 DOI: 10.1038/s41551-017-0040] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Pancreatic cancers are usually detected at an advanced stage and have poor prognosis. About one fifth of these arise from pancreatic cystic lesions. Yet not all lesions are precancerous, and imaging tools lack adequate accuracy for distinguishing precancerous from benign cysts. Therefore, decisions on surgical resection usually rely on endoscopic ultrasound-guided fine needle aspiration (EUS-FNA). Unfortunately, cyst fluid often contains few cells, and fluid chemical analysis lacks accuracy, resulting in dire consequences, including unnecessary pancreatic surgery for benign cysts and the development of cancer. Here, we report an optical spectroscopic technique, based on a spatial gating fibre-optic probe, that predicts the malignant potential of pancreatic cystic lesions during routine diagnostic EUS-FNA procedures. In a double-blind prospective study in 25 patients, with 14 cysts measured in vivo and 13 postoperatively, the technique achieved an overall accuracy of 95%, with a 95%confidence interval of 78-99%, in cysts with definitive diagnosis.
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Affiliation(s)
- Lei Zhang
- Center for Advanced Biomedical Imaging and Photonics, Department of Obstetrics, Gynecology and Reproductive Biology, Harvard University, Boston, Massachusetts 02215 USA
| | - Douglas K Pleskow
- Division of Gastroenterology, Department of Medicine, Harvard University, Boston, Massachusetts 02215 USA
| | - Vladimir Turzhitsky
- Center for Advanced Biomedical Imaging and Photonics, Department of Obstetrics, Gynecology and Reproductive Biology, Harvard University, Boston, Massachusetts 02215 USA
| | - Eric U Yee
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard University, Boston, Massachusetts 02215 USA
| | - Tyler M Berzin
- Division of Gastroenterology, Department of Medicine, Harvard University, Boston, Massachusetts 02215 USA
| | - Mandeep Sawhney
- Division of Gastroenterology, Department of Medicine, Harvard University, Boston, Massachusetts 02215 USA
| | - Shweta Shinagare
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard University, Boston, Massachusetts 02215 USA
| | - Edward Vitkin
- Center for Advanced Biomedical Imaging and Photonics, Department of Obstetrics, Gynecology and Reproductive Biology, Harvard University, Boston, Massachusetts 02215 USA
| | - Yuri Zakharov
- Center for Advanced Biomedical Imaging and Photonics, Department of Obstetrics, Gynecology and Reproductive Biology, Harvard University, Boston, Massachusetts 02215 USA
| | - Umar Khan
- Center for Advanced Biomedical Imaging and Photonics, Department of Obstetrics, Gynecology and Reproductive Biology, Harvard University, Boston, Massachusetts 02215 USA
| | - Fen Wang
- Division of Gastroenterology, Department of Medicine, Harvard University, Boston, Massachusetts 02215 USA
| | - Jeffrey D Goldsmith
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard University, Boston, Massachusetts 02215 USA
| | - Saveli Goldberg
- Division of Biostatistics and Biomathematics, Massachusetts General Hospital, Harvard University, Boston, Massachusetts 02215 USA
| | - Ram Chuttani
- Division of Gastroenterology, Department of Medicine, Harvard University, Boston, Massachusetts 02215 USA
| | - Irving Itzkan
- Center for Advanced Biomedical Imaging and Photonics, Department of Obstetrics, Gynecology and Reproductive Biology, Harvard University, Boston, Massachusetts 02215 USA
| | - Le Qiu
- Center for Advanced Biomedical Imaging and Photonics, Department of Obstetrics, Gynecology and Reproductive Biology, Harvard University, Boston, Massachusetts 02215 USA
| | - Lev T Perelman
- Center for Advanced Biomedical Imaging and Photonics, Department of Obstetrics, Gynecology and Reproductive Biology, Harvard University, Boston, Massachusetts 02215 USA.,Division of Gastroenterology, Department of Medicine, Harvard University, Boston, Massachusetts 02215 USA.,Biological and Biomedical Sciences Program, Harvard University, Boston, Massachusetts 02215 USA
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Kanick SC, McClatchy DM, Krishnaswamy V, Elliott JT, Paulsen KD, Pogue BW. Sub-diffusive scattering parameter maps recovered using wide-field high-frequency structured light imaging. BIOMEDICAL OPTICS EXPRESS 2014; 5:3376-90. [PMID: 25360357 PMCID: PMC4206309 DOI: 10.1364/boe.5.003376] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Revised: 08/22/2014] [Accepted: 08/25/2014] [Indexed: 05/03/2023]
Abstract
This study investigates the hypothesis that structured light reflectance imaging with high spatial frequency patterns [Formula: see text] can be used to quantitatively map the anisotropic scattering phase function distribution [Formula: see text] in turbid media. Monte Carlo simulations were used in part to establish a semi-empirical model of demodulated reflectance ([Formula: see text]) in terms of dimensionless scattering [Formula: see text] and [Formula: see text], a metric of the first two moments of the [Formula: see text] distribution. Experiments completed in tissue-simulating phantoms showed that simultaneous analysis of [Formula: see text] spectra sampled at multiple [Formula: see text] in the frequency range [0.05-0.5] [Formula: see text] allowed accurate estimation of both [Formula: see text] in the relevant tissue range [0.4-1.8] [Formula: see text], and [Formula: see text] in the range [1.4-1.75]. Pilot measurements of a healthy volunteer exhibited [Formula: see text]-based contrast between scar tissue and surrounding normal skin, which was not as apparent in wide field diffuse imaging. These results represent the first wide-field maps to quantify sub-diffuse scattering parameters, which are sensitive to sub-microscopic tissue structures and composition, and therefore, offer potential for fast diagnostic imaging of ultrastructure on a size scale that is relevant to surgical applications.
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Sperm preparation: state-of-the-art--physiological aspects and application of advanced sperm preparation methods. Asian J Androl 2011; 14:260-9. [PMID: 22138904 DOI: 10.1038/aja.2011.133] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
For assisted reproduction technologies (ART), numerous techniques were developed to isolate spermatozoa capable of fertilizing oocytes. While early methodologies only focused on isolating viable, motile spermatozoa, with progress of ART, particularly intracytoplasmic sperm injection (ICSI), it became clear that these parameters are insufficient for the identification of the most suitable spermatozoon for fertilization. Conventional sperm preparation techniques, namely, swim-up, density gradient centrifugation and glass wool filtration, are not efficient enough to produce sperm populations free of DNA damage, because these techniques are not physiological and not modeled on the stringent sperm selection processes taking place in the female genital tract. These processes only allow one male germ cell out of tens of millions to fuse with the oocyte. Sites of sperm selection in the female genital tract are the cervix, uterus, uterotubal junction, oviduct, cumulus oophorus and the zona pellucida. Newer strategies of sperm preparation are founded on: (i) morphological assessment by means of 'motile sperm organelle morphological examination (MSOME)'; (ii) electrical charge; and (iii) molecular binding characteristics of the sperm cell. Whereas separation methods based on electrical charge take advantage of the sperm's adherence to a test tube surface or separate in an electrophoresis, molecular binding techniques use Annexin V or hyaluronic acid (HA) as substrates. Techniques in this category are magnet-activated cell sorting, Annexin V-activated glass wool filtration, flow cytometry and picked spermatozoa for ICSI (PICSI) from HA-coated dishes and HA-containing media. Future developments may include Raman microspectrometry, confocal light absorption and scattering spectroscopic microscopy and polarization microscopy.
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Su X, Qiu Y, Marquez-Curtis L, Gupta M, Capjack CE, Rozmus W, Janowska-Wieczorek A, Tsui YY. Label-free and noninvasive optical detection of the distribution of nanometer-size mitochondria in single cells. JOURNAL OF BIOMEDICAL OPTICS 2011; 16:067003. [PMID: 21721824 DOI: 10.1117/1.3583577] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
A microfluidic flow cytometric technique capable of obtaining information on nanometer-sized organelles in single cells in a label-free, noninvasive optical manner was developed. Experimental two-dimensional (2D) light scattering patterns from malignant lymphoid cells (Jurkat cell line) and normal hematopoietic stem cells (cord blood CD34+ cells) were compared with those obtained from finite-difference time-domain simulations. In the simulations, we assumed that the mitochondria were randomly distributed throughout a Jurkat cell, and aggregated in a CD34+ cell. Comparison of the experimental and simulated light scattering patterns led us to conclude that distinction from these two types of cells may be due to different mitochondrial distributions. This observation was confirmed by conventional confocal fluorescence microscopy. A method for potential cell discrimination was developed based on analysis of the 2D light scattering patterns. Potential clinical applications using mitochondria as intrinsic biological markers in single cells were discussed in terms of normal cells (CD34+ cell and lymphocytes) versus malignant cells (THP-1 and Jurkat cell lines).
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Affiliation(s)
- Xuantao Su
- Shandong University, School of Control Science & Engineering, Department of Biomedical Engineering, Jinan, China.
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Floume T, Syms RRA, Darzi AW, Hanna GB. Optical, thermal, and electrical monitoring of radio-frequency tissue modification. JOURNAL OF BIOMEDICAL OPTICS 2010; 15:018003. [PMID: 20210489 DOI: 10.1117/1.3323089] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Radio-frequency (rf) tissue fusion involves the sealing of tissue between two electrodes delivering rf currents. Applications include small bowel fusion following anastomosis. The mechanism of adhesion is poorly understood, but one hypothesis is that rf modification is correlated to thermal damage and dehydration. A multimodal monitoring system capable of acquiring tissue temperature, electrical impedance, and optical transmittance at 1325-nm wavelength during rf delivery by a modified Ligasure fusion tool is presented. Measurements carried out on single layers of ex vivo porcine small bowel tissue heated at approximately 500-kHz frequency are correlated with observation of water evaporation and histological studies on full seals. It is shown that the induced current generates a rapid quasilinear rise of temperature until the boiling point of water, that changes in tissue transmittance occur before impedance control is possible, and that a decrease in transmission occurs at typical denaturation temperatures. Experimental results are compared with a biophysical model for tissue temperature and a rate equation model for thermal damage.
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Affiliation(s)
- Timmy Floume
- Imperial College London, Department of Electrical and Electronic Engineering, St Mary's Hospital, Department of Bio Surgery and Surgical Technology, London, United Kingdom.
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Huang P, Hunter M, Georgakoudi I. Confocal light scattering spectroscopic imaging system for in situ tissue characterization. APPLIED OPTICS 2009; 48:2595-2599. [PMID: 19412220 DOI: 10.1364/ao.48.002595] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We report on the design and construction of a confocal light scattering spectroscopic imaging system aimed ultimately to conduct depth-resolved characterization of biological tissues. The confocal sectioning ability of the system is demonstrated using a two-layer sample consisting of a 200 microm thick cancer cell layer on top of a scattering layer doped with a green absorber. The measurement results demonstrate that distinct light scattering signals can be isolated from each layer with an axial and a lateral resolution of 30 and 27 microm, respectively. Such a system is expected to have significant applications in the areas of tissue engineering and disease diagnostics and monitoring.
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Affiliation(s)
- Peter Huang
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, Massachusetts 02155, USA
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7
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Floume T, Syms RRA, Darzi AW, Hanna GB. Real-time optical monitoring of radio-frequency tissue fusion by continuous wave transmission spectroscopy. JOURNAL OF BIOMEDICAL OPTICS 2008; 13:064006. [PMID: 19123653 DOI: 10.1117/1.3006062] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Radio-frequency (RF) tissue fusion is a novel method of tissue approximation that can seal tissue without the need for sutures or staples, based on the combined effects of heat and pressure on the apposed tissue surfaces. RF delivery must be controlled and optimized to obtain a reproducible, reliable seal. We use real-time optical measurements to improve understanding of the tissue modifications induced by RF fusion. The main macroscopic transformations are thermal denaturation and dehydration. Light propagation in tissue is a function of both and therefore should provide interesting insight into the dynamic of occurring phenomena. Quantification by continuous wave technique has proven challenging. We proposed an algorithm based on the measurement of the absolute transmittance of the tissue, making use of the modified Beer-Lambert law. The experimental method and the data algorithm are demonstrated by RF fusion of porcine small bowel. The proposed optical measurement modality is well adapted to modern surgical instrumentation used for minimally invasive procedures.
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Affiliation(s)
- Timmy Floume
- Imperial College, Electrical and Electronic Engineering Department Optical and Semiconductor Device Group, Exhibition Road, London, SW7 2BT.
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Itzkan I, Qiu L, Fang H, Zaman MM, Vitkin E, Ghiran IC, Salahuddin S, Modell M, Andersson C, Kimerer LM, Cipolloni PB, Lim KH, Freedman SD, Bigio I, Sachs BP, Hanlon EB, Perelman LT. Confocal light absorption and scattering spectroscopic microscopy monitors organelles in live cells with no exogenous labels. Proc Natl Acad Sci U S A 2007; 104:17255-60. [PMID: 17956980 PMCID: PMC2077242 DOI: 10.1073/pnas.0708669104] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2007] [Indexed: 12/20/2022] Open
Abstract
This article reports the development of an optical imaging technique, confocal light absorption and scattering spectroscopic (CLASS) microscopy, capable of noninvasively determining the dimensions and other physical properties of single subcellular organelles. CLASS microscopy combines the principles of light-scattering spectroscopy (LSS) with confocal microscopy. LSS is an optical technique that relates the spectroscopic properties of light elastically scattered by small particles to their size, refractive index, and shape. The multispectral nature of LSS enables it to measure internal cell structures much smaller than the diffraction limit without damaging the cell or requiring exogenous markers, which could affect cell function. Scanning the confocal volume across the sample creates an image. CLASS microscopy approaches the accuracy of electron microscopy but is nondestructive and does not require the contrast agents common to optical microscopy. It provides unique capabilities to study functions of viable cells, which are beyond the capabilities of other techniques.
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Affiliation(s)
- Irving Itzkan
- *Biomedical Imaging and Spectroscopy Laboratory, Departments of Medicine and Obstetrics and Gynecology and Reproductive Biology, Beth Israel Deaconess Medical Center, Harvard University, Boston, MA 02215
| | - Le Qiu
- *Biomedical Imaging and Spectroscopy Laboratory, Departments of Medicine and Obstetrics and Gynecology and Reproductive Biology, Beth Israel Deaconess Medical Center, Harvard University, Boston, MA 02215
| | - Hui Fang
- *Biomedical Imaging and Spectroscopy Laboratory, Departments of Medicine and Obstetrics and Gynecology and Reproductive Biology, Beth Israel Deaconess Medical Center, Harvard University, Boston, MA 02215
| | - Munir M. Zaman
- *Biomedical Imaging and Spectroscopy Laboratory, Departments of Medicine and Obstetrics and Gynecology and Reproductive Biology, Beth Israel Deaconess Medical Center, Harvard University, Boston, MA 02215
| | - Edward Vitkin
- *Biomedical Imaging and Spectroscopy Laboratory, Departments of Medicine and Obstetrics and Gynecology and Reproductive Biology, Beth Israel Deaconess Medical Center, Harvard University, Boston, MA 02215
| | - Ionita C. Ghiran
- *Biomedical Imaging and Spectroscopy Laboratory, Departments of Medicine and Obstetrics and Gynecology and Reproductive Biology, Beth Israel Deaconess Medical Center, Harvard University, Boston, MA 02215
| | - Saira Salahuddin
- *Biomedical Imaging and Spectroscopy Laboratory, Departments of Medicine and Obstetrics and Gynecology and Reproductive Biology, Beth Israel Deaconess Medical Center, Harvard University, Boston, MA 02215
| | - Mark Modell
- *Biomedical Imaging and Spectroscopy Laboratory, Departments of Medicine and Obstetrics and Gynecology and Reproductive Biology, Beth Israel Deaconess Medical Center, Harvard University, Boston, MA 02215
| | - Charlotte Andersson
- *Biomedical Imaging and Spectroscopy Laboratory, Departments of Medicine and Obstetrics and Gynecology and Reproductive Biology, Beth Israel Deaconess Medical Center, Harvard University, Boston, MA 02215
| | - Lauren M. Kimerer
- Department of Veterans Affairs, Medical Research Service, and Geriatric Research Education and Clinical Center, Bedford, MA 01730
| | - Patsy B. Cipolloni
- Department of Veterans Affairs, Medical Research Service, and Geriatric Research Education and Clinical Center, Bedford, MA 01730
| | - Kee-Hak Lim
- *Biomedical Imaging and Spectroscopy Laboratory, Departments of Medicine and Obstetrics and Gynecology and Reproductive Biology, Beth Israel Deaconess Medical Center, Harvard University, Boston, MA 02215
| | - Steven D. Freedman
- *Biomedical Imaging and Spectroscopy Laboratory, Departments of Medicine and Obstetrics and Gynecology and Reproductive Biology, Beth Israel Deaconess Medical Center, Harvard University, Boston, MA 02215
| | - Irving Bigio
- Departments of Physics and Biomedical Engineering, Boston University, Boston, MA 02215; and
| | - Benjamin P. Sachs
- *Biomedical Imaging and Spectroscopy Laboratory, Departments of Medicine and Obstetrics and Gynecology and Reproductive Biology, Beth Israel Deaconess Medical Center, Harvard University, Boston, MA 02215
| | - Eugene B. Hanlon
- Department of Veterans Affairs, Medical Research Service, and Geriatric Research Education and Clinical Center, Bedford, MA 01730
| | - Lev T. Perelman
- *Biomedical Imaging and Spectroscopy Laboratory, Departments of Medicine and Obstetrics and Gynecology and Reproductive Biology, Beth Israel Deaconess Medical Center, Harvard University, Boston, MA 02215
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Zheng JY, Tsai YC, Kadimcherla P, Zhang R, Shi J, Oyler GA, Boustany NN. The C-terminal transmembrane domain of Bcl-xL mediates changes in mitochondrial morphology. Biophys J 2007; 94:286-97. [PMID: 17766334 PMCID: PMC2134878 DOI: 10.1529/biophysj.107.104323] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We investigate the effect of mitochondrial localization and the Bcl-x(L) C-terminal transmembrane (TM) domain on mitochondrial morphology and subcellular light scattering. CSM 14.1 cell lines stably expressed yellow fluorescent protein (YFP), YFP-Bcl-x(L,) YFP-Bcl-x(L)-DeltaTM, containing the remainder of Bcl-x(L) after deletion of the last 21 amino acids corresponding to the TM domain, or YFP-TM, consisting of YFP fused at its C-terminal to the last 21 amino acids of Bcl-x(L). YFP-Bcl-x(L) and YFP-TM localized to the mitochondria. Their expression decreased the intensity ratio of wide-to-narrow angle forward scatter by subcellular organelles, and correlated with an increase in the proportion of mitochondria with an expanded matrix having greatly reduced intracristal spaces as observed by electron microscopy. Cells expressing YFP-TM also exhibited significant autophagy. In contrast, YFP-Bcl-x(L)-DeltaTM was diffusely distributed in the cells, and its expression did not alter light scattering or mitochondrial morphology compared with parental cells. Expression of YFP-Bcl-x(L) or YFP-Bcl-x(L)-DeltaTM provided significant resistance to staurosporine-induced apoptosis. Surprisingly however, YFP-TM expression also conferred a moderate level of cell death resistance in response to staurosporine. Taken together, our results suggest the existence of a secondary Bcl-x(L) function that is mediated by the transmembrane domain, alters mitochondrial morphology, and is distinct from BH3 domain sequestration.
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Affiliation(s)
- Jing-Yi Zheng
- Department of Biomedical Engineering, Rutgers University, Piscataway, New Jersey, USA
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Cottrell WJ, Wilson JD, Foster TH. Microscope enabling multimodality imaging, angle-resolved scattering, and scattering spectroscopy. OPTICS LETTERS 2007; 32:2348-50. [PMID: 17700781 DOI: 10.1364/ol.32.002348] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
We present the design, construction, and initial characterization of a multifunctional imaging/scattering spectroscopy system built around a commercial inverted microscope platform. The system enables co-registered brightfield, Fourier-filtered darkfield, and fluorescence imaging; monochromatic angle-resolved scattering measurements; and white-light wavelength-resolved scattering spectroscopy from the same field of view. A fiber-based illumination system provides illumination-wavelength flexibility and a good approximation to a point source. The performance of the system in its various data acquisition modes is experimentally verified using fluorescent microspheres. This multifunctional instrument provides a platform for studies on adherent cells from which the biophysical implications of subcellular light scattering can be studied in conjunction with sensitive fluorescence-based techniques.
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Affiliation(s)
- W J Cottrell
- Institute of Optics and Departments of Physics and of Imaging Sciences, University of Rochester, Rochester, NY 14642, USA
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Wilson JD, Foster TH. Characterization of lysosomal contribution to whole-cell light scattering by organelle ablation. JOURNAL OF BIOMEDICAL OPTICS 2007; 12:030503. [PMID: 17614706 DOI: 10.1117/1.2743971] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Angularly resolved light scattering measurements made at visible wavelengths have the ability to quantify subcellular morphology, with particular sensitivity to organelles the size of mitochondria and lysosomes. We have recently reported on a lysosome-staining-based method that provides scattering contrast between stained and unstained cells, and through the use of appropriate models, we extracted a size distribution and contribution to cellular light scattering that we attributed to lysosomes. We provide an independent measurement of the lysosomal size distribution and contribution to cellular light scattering by exploiting photodynamic ablation of lysosomes and observing its effect on angularly resolved light scattering measurements. From these measurements, we conclude that lysosomes scatter approximately 14% of the light from EMT6 cells at 633 nm and that their size distribution has a mean and standard deviation of 0.8 and 0.4 microm, respectively.
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Affiliation(s)
- Jeremy D Wilson
- University of Rochester, Department of Physics, Rochester, New York 14642, USA
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Perelman LT. Optical diagnostic technology based on light scattering spectroscopy for early cancer detection. Expert Rev Med Devices 2007; 3:787-803. [PMID: 17280544 DOI: 10.1586/17434440.3.6.787] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
This article reviews the application of optical diagnostic technology based on light scattering spectroscopy for minimally invasive detection of precancerous and early cancerous changes in a variety of organs. Optical spectroscopic techniques have shown promising results in the diagnosis of diseases at the cellular scale. They do not require tissue removal, can be performed in vivo and allow for real-time diagnosis. While fluorescence and Raman spectroscopy are most effective in revealing the molecular properties of tissue, the novel technique, light scattering spectroscopy, is capable of characterizing the structural properties of tissue at the cellular and subcellular scale.
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Affiliation(s)
- Lev T Perelman
- Harvard University, Department of ObGyn and Reproductive Biology, Biomedical Imaging and Spectroscopy Laboratory, Beth Israel Deaconess Medical Center, Dana 879, Boston, MA 02215, USA.
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Wilson JD, Cottrell WJ, Foster TH. Index-of-refraction-dependent subcellular light scattering observed with organelle-specific dyes. JOURNAL OF BIOMEDICAL OPTICS 2007; 12:014010. [PMID: 17343485 DOI: 10.1117/1.2437765] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Angularly resolved light scattering and wavelength-resolved darkfield scattering spectroscopy measurements were performed on intact, control EMT6 cells and cells stained with high-extinction lysosomal- or mitochondrial-localizing dyes. In the presence of the lysosomal-localizing dye NPe6, we observe changes in the details of light scattering from stained and unstained cells, which have both wavelength- and angular-dependent features. Analysis of measurements performed at several wavelengths reveals a reduced scattering cross section near the absorption maximum of the lysosomal-localizing dye. When identical measurements are made with cells loaded with a similar mitochondrial-localizing dye, HPPH, we find no evidence that staining mitochondria had any effect on the light scattering. Changes in the scattering properties of candidate populations of organelles induced by the addition of an absorber are modeled with Mie theory, and we find that any absorber-induced scattering response is very sensitive to the inherent refractive index of the organelle population. Our measurements and modeling are consistent with EMT6-cell-mitochondria having refractive indices close to those reported in the literature for organelles, approximately 1.4. The reduction in scattering cross section induced by NPe6 constrains the refractive index of lysosomes to be significantly higher. We estimate the refractive index of lysosomes in EMT6 cells to be approximately 1.6.
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Affiliation(s)
- Jeremy D Wilson
- University of Rochester, Department of Physics and Astronomy, Rochester, New York 14627, USA
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