1
|
Sobkowiak A, Fluks M, Kosyl E, Milewski R, Szpila M, Tamborski S, Szkulmowski M, Ajduk A. The number of nuclei in compacted embryos, assessed by optical coherence microscopy, is a non-invasive and robust marker of mouse embryo quality. Mol Hum Reprod 2024; 30:gaae012. [PMID: 38407286 PMCID: PMC10978378 DOI: 10.1093/molehr/gaae012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 01/15/2024] [Indexed: 02/27/2024] Open
Abstract
Optical coherence microscopy (OCM) visualizes nuclei in live, unlabeled cells. As most cells are uninucleated, the number of nuclei in embryos may serve as a proxy of the cell number, providing important information on developmental status of the embryo. Importantly, no other non-invasive method currently allows for the cell number count in compacted embryos. We addressed the question of whether OCM, by providing the number of nuclei in compacted mouse embryos, may help evaluate embryo quality. We subjected compacted embryonic Day 3 (E3.0: 72 h after onset of insemination) mouse embryos to OCM scanning and correlated nuclei number and developmental potential. Implantation was assessed using an outgrowth assay (in vitro model meant to reflect embryonic ability to implant in vivo). Embryos with more cells at E3.0 (>18 cells) were more likely to reach the blastocyst stage by E4.0 and E5.0 (P ≪ 0.001) and initiate hatching by E5.0 (P < 0.05) than those with fewer cells (<12 cells). Moreover, the number of cells at E3.0 strongly correlated with the total number of cells in E4.0 and E5.0 embryos (ρ = 0.71, P ≪ 0.001 and ρ = 0.61, P ≪ 0.001, respectively), also when only E4.0 and E5.0 blastocysts were considered (ρ = 0.58, P ≪ 0.001 and ρ = 0.56, P ≪ 0.001, respectively). Additionally, we observed a strong correlation between the number of cells at E3.0 and the number of trophectoderm cells in E4.0 and E5.0 blastocysts (ρ = 0.59, P ≪ 0.001 and ρ = 0.57, P ≪ 0.001, respectively). Importantly, embryos that had more cells at E3.0 (>18 cells) were also more likely to implant in vitro than their counterparts with fewer cells (<12 cells; P ≪ 0.001). Finally, we tested the safety of OCM imaging, demonstrating that OCM scanning affected neither the amount of reactive oxygen species nor mitochondrial activity in the embryos. OCM also did not hinder their preimplantation development, ability to implant in vitro, or to develop to term after transfer to recipient females. Our data indicate that OCM imaging provides important information on embryo quality. As the method seems to be safe for embryos, it could be a valuable addition to the current repertoire of embryo evaluation methods. However, our study was conducted only on mouse embryos, so the proposed protocol would require optimization in order to be applied in other species.
Collapse
Affiliation(s)
- Aleksandra Sobkowiak
- Department of Embryology, Institute of Developmental Biology and Biomedical Sciences, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Monika Fluks
- Department of Embryology, Institute of Developmental Biology and Biomedical Sciences, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Ewa Kosyl
- Department of Embryology, Institute of Developmental Biology and Biomedical Sciences, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Robert Milewski
- Department of Biostatistics and Medical Informatics, Medical University of Bialystok, Białystok, Poland
| | - Marcin Szpila
- Department of Embryology, Institute of Developmental Biology and Biomedical Sciences, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Szymon Tamborski
- Department of Biophotonics and Optical Engineering, Institute of Physics, Faculty of Physics, Astronomy, and Informatics, Nicolaus Copernicus University in Torun, Toruń, Poland
| | - Maciej Szkulmowski
- Department of Biophotonics and Optical Engineering, Institute of Physics, Faculty of Physics, Astronomy, and Informatics, Nicolaus Copernicus University in Torun, Toruń, Poland
| | - Anna Ajduk
- Department of Embryology, Institute of Developmental Biology and Biomedical Sciences, Faculty of Biology, University of Warsaw, Warsaw, Poland
| |
Collapse
|
2
|
Masuda Y, Hasebe R, Kuromi Y, Hishinuma M, Ohbayashi T, Nishimura R. Hatchability evaluation of bovine IVF embryos using OCT-based 3D image analysis. J Reprod Dev 2023; 69:239-245. [PMID: 37574267 PMCID: PMC10602767 DOI: 10.1262/jrd.2023-009] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Accepted: 07/10/2023] [Indexed: 08/15/2023] Open
Abstract
Although embryo transfer is widely applied in cattle, many of the transferred embryos do not result in pregnancy. To determine a new parameter for bovine embryo evaluation, we investigated the relationships between in vitro hatchability and embryo morphological parameters using optical coherence tomography (OCT) that we established recently. Bovine embryos were obtained from Japanese Black cattle by in vitro fertilization (IVF). The quality of the blastocysts was examined under an inverted microscope and confirmed as Codes 1-3 according to the IETS standards for embryo evaluation. The OCT images of the embryos were captured on Day 7 after IVF, and the embryos were cultured until Day 9 to determine their hatchability. During OCT, the embryos were irradiated with near-infrared light for a few minutes to obtain three-dimensional images. In total, 22 parameters were assessed for each of the 42 embryos, of which 25 hatched (H embryos) and 17 did not (NH embryos). The thickness of the trophectoderm (TE) and TE+zona pellucida (ZP) was lesser, and the volumes of the TE, ZP, blastocoel, and whole embryo and blastocoel diameter were greater in the H embryos than in the NH embryos. PCA identified that the increase in the blastocoel-related value along with the decrease in the thickness-related value of the TE and/or ZP could be indicators for evaluating the hatchability of bovine IVF embryos. These results support the idea that OCT-captured structural data of blastocyst-stage embryos can be used as a potential model to predict the quality of bovine embryos.
Collapse
Affiliation(s)
- Yasumitsu Masuda
- Department of Animal Science, Tottori Livestock Research Center, Tottori 680-8553, Japan
| | - Ryo Hasebe
- SCREEN Holdings Co., Ltd., Kyoto 612-8486, Japan
| | | | - Mitsugu Hishinuma
- Laboratory of Theriogenology, Joint Department of Veterinary Medicine, Faculty of Agriculture, Tottori University, Tottori 680-8553, Japan
| | - Tetsuya Ohbayashi
- Organization for Research Initiative and Promotion, Tottori University, Tottori 680-8553, Japan
| | - Ryo Nishimura
- Laboratory of Theriogenology, Joint Department of Veterinary Medicine, Faculty of Agriculture, Tottori University, Tottori 680-8553, Japan
| |
Collapse
|
3
|
Zhang J, Mazlin V, Fei K, Boccara AC, Yuan J, Xiao P. Time-domain full-field optical coherence tomography (TD-FF-OCT) in ophthalmic imaging. Ther Adv Chronic Dis 2023; 14:20406223231170146. [PMID: 37152350 PMCID: PMC10161339 DOI: 10.1177/20406223231170146] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2022] [Accepted: 03/29/2023] [Indexed: 05/09/2023] Open
Abstract
Ocular imaging plays an irreplaceable role in the evaluation of eye diseases. Developing cellular-resolution ophthalmic imaging technique for more accurate and effective diagnosis and pathogenesis analysis of ocular diseases is a hot topic in the cross-cutting areas of ophthalmology and imaging. Currently, ocular imaging with traditional optical coherence tomography (OCT) is limited in lateral resolution and thus can hardly resolve cellular structures. Conventional OCT technology obtains ultra-high resolution at the expense of a certain imaging range and cannot achieve full field of view imaging. In the early years, Time-domain full-field OCT (TD-FF-OCT) has been mainly used for ex vivo ophthalmic tissue studies, limited by the low speed and low full-well capacity of existing two-dimensional (2D) cameras. The recent improvements in system design opened new imaging possibilities for in vivo applications thanks to its distinctive optical properties of TD-FF-OCT such as a spatial resolution almost insensitive to aberrations, and the possibility to control the curvature of the optical slice. This review also attempts to look at the future directions of TD-FF-OCT evolution, for example, the potential transfer of the functional-imaging dynamic TD-FF-OCT from the ex vivo into in vivo use and its expected benefit in basic and clinical ophthalmic research. Through non-invasive, wide-field, and cellular-resolution imaging, TD-FF-OCT has great potential to be the next-generation imaging modality to improve our understanding of human eye physiology and pathology.
Collapse
Affiliation(s)
- Jinze Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Viacheslav Mazlin
- ESPCI Paris, PSL University, CNRS, Langevin Institute, Paris, France
| | - Keyi Fei
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | | | - Jin Yuan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Jinsui Road 7, Guangzhou 510060, Guangdong, China
| | - Peng Xiao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Jinsui Road 7, Guangzhou 510060, Guangdong, China
| |
Collapse
|
4
|
Lin SE, Jheng DY, Hsu KY, Liu YR, Huang WH, Lee HC, Tsai CC. Rapid pseudo-H&E imaging using a fluorescence-inbuilt optical coherence microscopic imaging system. BIOMEDICAL OPTICS EXPRESS 2021; 12:5139-5158. [PMID: 34513247 PMCID: PMC8407814 DOI: 10.1364/boe.431586] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 07/12/2021] [Accepted: 07/13/2021] [Indexed: 06/13/2023]
Abstract
A technique using Linnik-based optical coherence microscopy (OCM), with built-in fluorescence microscopy (FM), is demonstrated here to describe cellular-level morphology for fresh porcine and biobank tissue specimens. The proposed method utilizes color-coding to generate digital pseudo-H&E (p-H&E) images. Using the same camera, colocalized FM images are merged with corresponding morphological OCM images using a 24-bit RGB composition process to generate position-matched p-H&E images. From receipt of dissected fresh tissue piece to generation of stitched images, the total processing time is <15 min for a 1-cm2 specimen, which is on average two times faster than frozen-section H&E process for fatty or water-rich fresh tissue specimens. This technique was successfully used to scan human and animal fresh tissue pieces, demonstrating its applicability for both biobank and veterinary purposes. We provide an in-depth comparison between p-H&E and human frozen-section H&E images acquired from the same metastatic sentinel lymph node slice (∼10 µm thick), and show the differences, like elastic fibers of a tiny blood vessel and cytoplasm of tumor cells. This optical sectioning technique provides histopathologists with a convenient assessment method that outputs large-field H&E-like images of fresh tissue pieces without requiring any physical embedment.
Collapse
Affiliation(s)
- Sey-En Lin
- AcuSolutions Inc., 3F., No. 2, Ln. 263, Chongyang Rd., Nangang Dist., Taipei, Taiwan
- Department of Anatomic Pathology, New Taipei Municipal Tucheng Hospital (Built and operated by Chang Gung Medical Foundation), New Taipei City, Taiwan
| | - Dong-Yo Jheng
- AcuSolutions Inc., 3F., No. 2, Ln. 263, Chongyang Rd., Nangang Dist., Taipei, Taiwan
| | - Kuang-Yu Hsu
- AcuSolutions Inc., 3F., No. 2, Ln. 263, Chongyang Rd., Nangang Dist., Taipei, Taiwan
| | - Yun-Ru Liu
- Joint Biobank, Office of Human Research, Taipei Medical University, Taipei, Taiwan
| | - Wei-Hsiang Huang
- Graduate Institute of Molecular and Comparative Pathobiology, School of Veterinary Medicine, National Taiwan University, Taipei, Taiwan
| | - Hsiang-Chieh Lee
- Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, Taiwan
- Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan
| | - Chien-Chung Tsai
- AcuSolutions Inc., 3F., No. 2, Ln. 263, Chongyang Rd., Nangang Dist., Taipei, Taiwan
| |
Collapse
|
5
|
Masuda Y, Hasebe R, Kuromi Y, Kobayashi M, Urataki K, Hishinuma M, Ohbayashi T, Nishimura R. Three-Dimensional Live Imaging of Bovine Preimplantation Embryos: A New Method for IVF Embryo Evaluation. Front Vet Sci 2021; 8:639249. [PMID: 33981741 PMCID: PMC8107228 DOI: 10.3389/fvets.2021.639249] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 03/11/2021] [Indexed: 12/21/2022] Open
Abstract
Conception rates for transferred bovine embryos are lower than those for artificial insemination. Embryo transfer (ET) is widely used in cattle but many of the transferred embryos fail to develop, thus, a more effective method for selecting bovine embryos suitable for ET is required. To evaluate the developmental potential of bovine preimplantation embryos (2-cell stage embryos and blastocysts), we have used the non-invasive method of optical coherence tomography (OCT) to obtain live images. The images were used to evaluate 22 parameters of blastocysts, such as the volume of the inner cell mass and the thicknesses of the trophectoderm (TE). Bovine embryos were obtained by in vitro fertilization (IVF) of the cumulus-oocyte complexes aspirated by ovum pick-up from Japanese Black cattle. The quality of the blastocysts was examined under an inverted microscope and all were confirmed to be Code1 according to the International Embryo Transfer Society standards for embryo evaluation. The OCT images of embryos were taken at the 2-cell and blastocyst stages prior to the transfer. In OCT, the embryos were irradiated with near-infrared light for a few minutes to capture three-dimensional images. Nuclei of the 2-cell stage embryos were clearly observed by OCT, and polynuclear cells at the 2-cell stage were also clearly found. With OCT, we were able to observe embryos at the blastocyst stage and evaluate their parameters. The conception rate following OCT (15/30; 50%) is typical for ETs and no newborn calves showed neonatal overgrowth or died, indicating that the OCT did not adversely affect the ET. A principal components analysis was unable to identify the parameters associated with successful pregnancy, while by using hierarchical clustering analysis, TE volume has been suggested to be one of the parameters for the evaluation of bovine embryo. The present results show that OCT imaging can be used to investigate time-dependent changes of IVF embryos. With further improvements, it should be useful for selecting high-quality embryos for transfer.
Collapse
Affiliation(s)
- Yasumitsu Masuda
- Department of Animal Science, Tottori Livestock Research Center, Tottori, Japan
| | | | | | | | - Kanako Urataki
- Laboratory of Theriogenology, Joint Department of Veterinary Medicine, Faculty of Agriculture, Tottori University, Tottori, Japan
| | - Mitsugu Hishinuma
- Laboratory of Theriogenology, Joint Department of Veterinary Medicine, Faculty of Agriculture, Tottori University, Tottori, Japan
| | - Tetsuya Ohbayashi
- Organization for Research Initiative and Promotion, Tottori University, Tottori, Japan
| | - Ryo Nishimura
- Laboratory of Theriogenology, Joint Department of Veterinary Medicine, Faculty of Agriculture, Tottori University, Tottori, Japan
| |
Collapse
|
6
|
Masuda Y, Hasebe R, Kuromi Y, Kobayashi M, Iwamoto M, Hishinuma M, Ohbayashi T, Nishimura R. Three-dimensional live imaging of bovine embryos by optical coherence tomography. J Reprod Dev 2021; 67:149-154. [PMID: 33487605 PMCID: PMC8075722 DOI: 10.1262/jrd.2020-151] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
While embryo transfer (ET) is widely practiced, many of the transferred embryos fail to develop in cattle. To establish a more effective method for selecting
bovine embryos for ET, here we quantified morphological parameters of living embryos using three-dimensional (3D) images non-invasively captured by optical
coherence tomography (OCT). Seven Japanese Black embryos produced by in vitro fertilization that had reached the expanded blastocyst stage
after 7 days of culture were transferred after imaged by OCT. Twenty-two parameters, including thickness and volumes of the inner cell mass, trophectoderm, and
zona pellucida, and volumes of blastocoel and whole embryo, were quantified from 3D images. Four of the seven recipients became pregnant. We suggest that these
22 parameters can be potentially employed to evaluate the quality of bovine embryos before ET.
Collapse
Affiliation(s)
- Yasumitsu Masuda
- Department of Animal Science, Tottori Livestock Research Center, Tottori 689-2503, Japan
| | - Ryo Hasebe
- SCREEN Holdings Co., Ltd., Kyoto 612-8486, Japan
| | | | | | - Misaki Iwamoto
- Laboratory of Theriogenology, Joint Department of Veterinary Medicine, Faculty of Agriculture, Tottori University, Tottori 680-8553, Japan
| | - Mitsugu Hishinuma
- Laboratory of Theriogenology, Joint Department of Veterinary Medicine, Faculty of Agriculture, Tottori University, Tottori 680-8553, Japan
| | - Tetsuya Ohbayashi
- Organization for Research Initiative and Promotion, Tottori University, Tottori 680-8550, Japan
| | - Ryo Nishimura
- Laboratory of Theriogenology, Joint Department of Veterinary Medicine, Faculty of Agriculture, Tottori University, Tottori 680-8553, Japan
| |
Collapse
|
7
|
Tian N, Lv DY, Yu J, Ma WY. Methotrexate impaired in-vivo matured mouse oocyte quality and the possible mechanisms. BMC Mol Cell Biol 2020; 21:51. [PMID: 32620073 PMCID: PMC7333412 DOI: 10.1186/s12860-020-00298-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Accepted: 06/29/2020] [Indexed: 12/30/2022] Open
Abstract
Background Methotrexate (MTX) is an antifolate agent which is widely used in clinic for treating malignancies, rheumatoid arthritis and ectopic pregnancy. As reported, MTX has side effects on gastrointestinal system, nervous system and reproductive system, while its potential damages on oocyte quality are still unclear. It is known that oocyte quality is essential for healthy conception and the forthcoming embryo development. Thus, this work studied the effects of MTX on the oocyte quality. Results We established MTX model mice by single treatment with 5 mg/Kg MTX. Both morphological and molecular biology studies were performed to assess the in-vivo matured oocytes quality and to analyze the related mechanisms. The in-vivo matured oocytes from MTX-treated mice had poor in-vitro fertilization ability, and the resulting embryo formation rates and blastocyst quality were lower than the control group. We found that the in-vivo matured MTX-treated mouse oocytes displayed abnormal transcript expressions for genes of key enzymes in the folate cycles. MTX increased the rate of abnormal chromosome alignment and affected the regulation of chromosome separation via disrupting the spindle morphology and reducing the mRNA expressions of MAD2 and Sgo1. MTX reduced the DNA methylation levels in the in-vivo matured oocytes, and further studies showed that MTX altered the expressions of DNMT1 and DNMT 3b, and may also affect the levels of the methyl donor and its metabolite. Conclusions MTX impaired the in-vivo matured mouse oocyte quality by disturbing folate metabolism and affecting chromosome stability and methylation modification.
Collapse
Affiliation(s)
- Ning Tian
- Physical Science and Technical College, Shenyang Normal University, No. 253 Huanghe North Street, Huanggu District, Shenyang City, 110034, Liaoning Province, China.
| | - Dan-Yu Lv
- Department of Histology and Embryology, School of Basic Medical Sciences, Peking University Health Science Center, No. 38 Xueyuan Road, Haidian District, Beijing, 100191, China
| | - Ji Yu
- Physical Science and Technical College, Shenyang Normal University, No. 253 Huanghe North Street, Huanggu District, Shenyang City, 110034, Liaoning Province, China
| | - Wan-Yun Ma
- State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Haidian District, Beijing, 100084, China
| |
Collapse
|
8
|
Moore EL, Wang S, Larina IV. Staging mouse preimplantation development in vivo using optical coherence microscopy. JOURNAL OF BIOPHOTONICS 2019; 12:e201800364. [PMID: 30578614 PMCID: PMC6470020 DOI: 10.1002/jbio.201800364] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 12/10/2018] [Accepted: 12/19/2018] [Indexed: 05/19/2023]
Abstract
In mammals, preimplantation development primarily occurs in the oviduct (or fallopian tube) where fertilized oocytes migrate through, develop and divide as they prepare for implantation in the uterus. Studies of preimplantation development currently rely on ex vivo experiments with the embryos cultured outside of the oviduct, neglecting the native environment for embryonic growth. This prevents the understanding of the natural process of preimplantation development and the roles of the oviduct in early embryonic health. Here, we report an in vivo optical imaging approach enabling high-resolution visualizations of developing embryos in the mouse oviduct. By combining optical coherence microscopy (OCM) and a dorsal imaging window, the subcellular structures and morphologies of unfertilized oocytes, zygotes and preimplantation embryos can be well resolved in vivo, allowing for the staging of development. We present the results together with bright-field microscopy images to show the comparable imaging quality. As the mouse is a well-established model with a variety of genetic engineering strategies available, the in vivo imaging approach opens great opportunities to investigate how the oviduct and early embryos interact to prepare for successful implantation. This knowledge could have beneficial impact on understanding infertility and improving in vitro fertilization. OCM through a dorsal imaging window enables high-resolution imaging and staging of mouse preimplantation embryos in vivo in the oviduct.
Collapse
Affiliation(s)
- Emma L. Moore
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, U.S.A
| | - Shang Wang
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, U.S.A
| | - Irina V. Larina
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, U.S.A
| |
Collapse
|
9
|
Zhu Y, Gao W. Single-shot wavelength-independent phase-shifting method for full-field optical coherence tomography. APPLIED OPTICS 2019; 58:806-813. [PMID: 30874124 DOI: 10.1364/ao.58.000806] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Accepted: 12/20/2018] [Indexed: 06/09/2023]
Abstract
One limitation of a piezoelectric translator-based phase-shifting method in full-field optical coherence tomography (FF-OCT) is that there exist interference residuals because a light source with broadband is used. In this work, an achromatic phase-shifting method was proposed in which a linear polarizer and a quarter-wave plate were employed to generate the circularly polarized light in the reference arm of a basic Linnik interferometer. The light field reflected from the reference arm is supposed with the unpolarized light backscattered from the sample when the path difference is within the coherence length of the light source. A first phase difference of π/2 can be generated on the propagation of superposed light beams through the polarized beam splitter. An additional phase difference of π/2 can be obtained by the proposed numerical method, thus producing the similar effects as the four-frame phase-shifting way. An en face tomographic image can be obtained with a single-shot in this new FF-OCT system. The axial and lateral resolutions of the system are around 1.4 μm and 0.8 μm, respectively. The system offers a dynamic range of ∼56 dB and an imaging rate of 30 fps. Tomographic images of Intel microchip, onion cells, and microcracks in the glass were displayed with clear substructures. This article aims at producing fringe-free OCT images in a single shot.
Collapse
|
10
|
Caujolle S, Cernat R, Silvestri G, Marques MJ, Bradu A, Feuchter T, Robinson G, Griffin DK, Podoleanu A. Speckle variance OCT for depth resolved assessment of the viability of bovine embryos. BIOMEDICAL OPTICS EXPRESS 2017; 8:5139-5150. [PMID: 29188109 PMCID: PMC5695959 DOI: 10.1364/boe.8.005139] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 09/14/2017] [Accepted: 09/24/2017] [Indexed: 06/07/2023]
Abstract
The morphology of embryos produced by in vitro fertilization (IVF) is commonly used to estimate their viability. However, imaging by standard microscopy is subjective and unable to assess the embryo on a cellular scale after compaction. Optical coherence tomography is an imaging technique that can produce a depth-resolved profile of a sample and can be coupled with speckle variance (SV) to detect motion on a micron scale. In this study, day 7 post-IVF bovine embryos were observed either short-term (10 minutes) or long-term (over 18 hours) and analyzed by swept source OCT and SV to resolve their depth profile and characterize micron-scale movements potentially associated with viability. The percentage of en face images showing movement at any given time was calculated as a method to detect the vital status of the embryo. This method could be used to measure the levels of damage sustained by an embryo, for example after cryopreservation, in a rapid and non-invasive way.
Collapse
Affiliation(s)
- S. Caujolle
- Applied Optics Group, School of Physical Sciences, University of Kent, Canterbury, CT2 7NH, UK
- NKT Photonics A/S, Blokken 84, 3460 Birkerød, Zealand, Denmark
- contributed equally to this work
| | - R. Cernat
- Applied Optics Group, School of Physical Sciences, University of Kent, Canterbury, CT2 7NH, UK
- contributed equally to this work
| | - G. Silvestri
- School of Biosciences, University of Kent, Canterbury, CT2 7AF, UK
- contributed equally to this work
| | - M. J. Marques
- Applied Optics Group, School of Physical Sciences, University of Kent, Canterbury, CT2 7NH, UK
| | - A. Bradu
- Applied Optics Group, School of Physical Sciences, University of Kent, Canterbury, CT2 7NH, UK
| | - T. Feuchter
- NKT Photonics A/S, Blokken 84, 3460 Birkerød, Zealand, Denmark
| | - G. Robinson
- School of Biosciences, University of Kent, Canterbury, CT2 7AF, UK
| | - D. K. Griffin
- School of Biosciences, University of Kent, Canterbury, CT2 7AF, UK
| | - A. Podoleanu
- Applied Optics Group, School of Physical Sciences, University of Kent, Canterbury, CT2 7NH, UK
| |
Collapse
|
11
|
Abstract
Imaging of living cells based on traditional fluorescence and confocal laser scanning microscopy has delivered an enormous amount of information critical for understanding biological processes in single cells. However, the requirement for a high numerical aperture and fluorescent markers still limits researchers’ ability to visualize the cellular architecture without causing short- and long-term photodamage. Optical coherence microscopy (OCM) is a promising alternative that circumvents the technical limitations of fluorescence imaging techniques and provides unique access to fundamental aspects of early embryonic development, without the requirement for sample pre-processing or labeling. In the present paper, we utilized the internal motion of cytoplasm, as well as custom scanning and signal processing protocols, to effectively reduce the speckle noise typical for standard OCM and enable high-resolution intracellular time-lapse imaging. To test our imaging system we used mouse and pig oocytes and embryos and visualized them through fertilization and the first embryonic division, as well as at selected stages of oogenesis and preimplantation development. Because all morphological and morphokinetic properties recorded by OCM are believed to be biomarkers of oocyte/embryo quality, OCM may represent a new chapter in imaging-based preimplantation embryo diagnostics.
Collapse
|
12
|
Wong CY, Mills JK. Automation and optimization of multi-pulse laser zona drilling of mouse embryos during embryo biopsy. IEEE Trans Biomed Eng 2016; 64:629-636. [DOI: 10.1109/tbme.2016.2571060] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|