אנו מודים לחברי מעבדת אלטו לדיונים מועילים. אנו מודים גם להדמיה מתקן מולקולרי ותאי במרכז רפואי UT Southwestern, במיוחד ד&quot;ר כריס גילפין, טום Januszewski, וורי מילר למומחיות וייעוץ טכניים. אנו מודים גם לד&quot;ר Xionan דונג לקריאה ביקורתית של כתב היד. עבודה זו נתמכת על ידי מענק NIH AI083359 לNMA

<ol>
	<li>Schmolze, D. B., Standley, C., Fogarty, K. E., Fischer, A. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Advances+in+microscopy+techniques.">Advances in microscopy techniques.</a> Arch. Pathol. Lab Med. 135, 255-263 (2011).</li><li>Giepmans, B. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bridging+fluorescence+microscopy+and+electron+microscopy.">Bridging fluorescence microscopy and electron microscopy.</a> Histochem. Cell Biol. 130, 211-217 (2008).</li><li>Mayhew, T. M., Muhlfeld, C., Vanhecke, D., Ochs, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+review+of+recent+methods+for+efficiently+quantifying+immunogold+and+other+nanoparticles+using+TEM+sections+through+cells,+tissues+and+organs.">A review of recent methods for efficiently quantifying immunogold and other nanoparticles using TEM sections through cells, tissues and organs.</a> Ann. Anat. 191, 153-170 (2009).</li><li>Razi, M., Tooze, S. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Correlative+light+and+electron+microscopy.">Correlative light and electron microscopy.</a> Methods Enzymol. 452, 261-275 (2009).</li><li>Svitkina, T. M., Borisy, G. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Correlative+light+and+electron+microscopy+of+the+cytoskeleton+of+cultured+cells.">Correlative light and electron microscopy of the cytoskeleton of cultured cells.</a> Methods Enzymol. 298, 570-592 (1998).</li><li>van Weering, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intracellular+membrane+traffic+at+high+resolution.">Intracellular membrane traffic at high resolution.</a> Methods Cell Biol. 96, 619-648 (2010).</li><li>Polishchuk, R. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Correlative+light-electron+microscopy+reveals+the+tubular-saccular+ultrastructure+of+carriers+operating+between+Golgi+apparatus+and+plasma+membrane.">Correlative light-electron microscopy reveals the tubular-saccular ultrastructure of carriers operating between Golgi apparatus and plasma membrane.</a> J. Cell Biol. 148, 45-58 (2000).</li><li>Lim, J., Danuser, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Live+Cell+Imaging+of+F-actin+Dynamics+via+Fluorescent+Speckle+Microscopy+(FSM).">Live Cell Imaging of F-actin Dynamics via Fluorescent Speckle Microscopy (FSM).</a> J. Vis. Exp. (30), e1325 (2009).</li><li>Selyunin, A. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+assembly+of+a+GTPase-kinase+signalling+complex+by+a+bacterial+catalytic+scaffold.">The assembly of a GTPase-kinase signalling complex by a bacterial catalytic scaffold.</a> Nature. 469, 107-111 (2011).</li><li>Semwogerere, D., Weeks, E. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Confocal Microscopy in Encyclopedia of Biomaterials and Biomedical Engineering. , (2005).</li></ol>

אין ניגודי אינטרסים מוכרזים.

השיטה שהוצגה כאן מאפשרת העברה הישירה של חלבונים מטוהרים, חומצות גרעין, או מולקולות קטנות לציטופלסמה האיקריוטים ומאפשרת ניתוח אולטרה ברזולוציה גבוהה באמצעות המתאם של מיקרוסקופיה ניאון ואלקטרון. השימוש בשיטה זו הוא פשוט אך חזק וניתן לבצעו בבית עם מתקנים רבים קיימים ?...

<table border="1" style=";text-align:right;direction:rtl"><tbody><tr><td> שם המגיב </td><td> חברה </td><td> מספר קטלוגים </td><td> תגובות </td></tr><tr><td> Coverslip Photoetched ופלייט Live-תא </td><td> מאטק </td><td> P35G-2-14-CGRD </td><td></td></tr><tr><td> טקסס האדומה </td><td> Invitrogen </td><td> D3329 </td><td></td></tr><tr><td> מפל הכחול </td><td> Invitrogen </td><td> D7132 </td><td></td></tr><tr><td> Rhodamine התיוג Kit </td><td> Thermo Scientific </td><td> 53002 </td><td></td></tr><tr><td> יחידת הסינון צנטריפוגלי מיקרומטר 0.22 </td><td> Millipore </td><td> UFC30GV00 </td><td></td></tr><tr><td> פיפטות הזכוכית ורוסיליקט </td><td> סאטר מכשירים </td><td> BF100-50-10 </td><td></td></tr><tr><td> Micropipette פולר </td><td> סאטר מכשירים </td><td> דגם P-97 </td><td> השתמש בתכנית המס &#39;4 לאחר ביצוע בדיקת רמפה </td></tr><tr><td> מערכת microinjection FemtoJet </td><td> אפנדורף </td><td> Injectman NI2 </td><td></td></tr><tr><td> נוזל להסרת coverslip </td><td> מאטק </td><td> PDCF 30 OS </td><td></td></tr><tr><td> מיקרוסקופ אלקטרוני ההילוכים Technai </td><td> פיי </td><td> Technai G2 BioTWIN </td><td></td></tr><tr><td> Ultramicrotombe </td><td> ליקה </td><td> EM UC6 </td><td></td></tr></tbody></table>

correlative light and electron microscopy (clem) as a tool to visualize microinjected molecules and their eukaryotic sub-cellular targets

תא האיקריוטים מסתמך על מורכב, פיקוח הדוק, ותאים כפותים קרום תפקודי שונים שישמרו קוטביות צורך ביוכימי לתפקוד תאי תקין. הבנה כיצד אנזימים, חלבונים ורכיבי cytoskeletal למשול ולשמור על פרדה ביוכימי זה היא אפוא בעלת חשיבות עליונה. השימוש במולקולות מתויגות fluorescently למקם ו / או תאים subcellular יפריעו הניבו שפע של ידע וההבנה מתקדמות של רגולציה הסלולרית שלנו. שיטות הדמיה כגון מיקרוסקופיה confocal ניאון ולהפוך את בירור עמדתו של מולקולה מתויגת fluorescently קטנה פשוטה יחסית, עם זאת הרזולוציה של מבנים קטנים מאוד מוגבלת 1. מצד השני, מיקרוסקופי אלקטרונים חשף פרטים של מורפולוגיה subcellular ברזולוציה גבוהה מאוד, אבל אופי סטטי עושה את זה קשה למדוד פרו דינמי מאודcesses עם דיוק 2,3. לפיכך, שילוב של מיקרוסקופ אור במיקרוסקופ אלקטרונים שלו המדגם, אור גומל כינה ומיקרוסקופי אלקטרונים (קלם) 4,5, מעניק את היתרונות הכפולים של הדמית ניאון ultrafast עם הרזולוציה גבוהה של מיקרוסקופיה אלקטרונית 6. טכניקה רבה עצמה זו יושמה כדי ללמוד על היבטים רבים של ביולוגיה של תא 5,7. מאז הקמתה, הליך זה גדל יכולתנו להבחין ארכיטקטורות ומורפולוגיות subcellular ברזולוציה גבוהה. כאן, אנו מציגים שיטה יעילה לביצוע microinjection המהיר ובעקבות קלם (1 איור). הליך קלם microinjection ניתן להשתמש כדי להציג את הכמויות ספציפיות של מולקולות קטנות ו / או חלבונים ישירות לתוך הציטופלסמה תא האיקריוטים ולחקור את ההשפעות ממילימטר לרזולוציה רב ננומטר (איור 2). הטכניקה מתבססת על microinjectingתאים גדלו על coverslips הליזר החרוט זכוכית gridded מודבק בתחתית של מנות תא חיים והדמיה עם שניהם מיקרוסקופיה ניאון ואלקטרון confocal. לוקליזציה של התא (הים) של עניין היא בנחייתם של דפוס הרשת, המועבר בקלות, יחד עם התאים של עניין, לשרף EPON משמש לקיבוע של דגימות וחתך לפני הניתוח מיקרוסקופי אלקטרונים (3 איור). כיסוי של הניאון וEM תמונות מאפשר למשתמש לקבוע את לוקליזציה subcellular כמו גם שינויים מורפולוגיים ו / או ultrastructural הנגרמים על ידי מולקולת microinjected ריבית (איור 4). טכניקה זו היא נוחה לנקודתי זמן שנעו בין 5 ≤ של עד כמה שעות, בהתאם לאופי של מדגם microinjected.

Watch this Scientific Journal Video about Correlative Light and Electron Microscopy CLEM as a Tool to Visualize Microinjected Molecules and their Eukaryotic Sub-cellular Targets at JoVE.com

Correlative Light and Electron Microscopy CLEM as a Tool to Visualize Microinjected Molecules and their Eukaryotic Sub-cellular Targets

טכניקת קלם הותאמה לנתח מורפולוגיה ultrastructural של קרומים, האברונים, ומבני subcellular מושפעים מולקולות microinjected. שיטה זו משלבת טכניקות רבות העצמה של המיקרומניפולציה / microinjection, מיקרוסקופיה confocal ניאון, וכן במיקרוסקופ אלקטרונים כדי לאפשר מילימטר לרזולוציה רבה ננומטר. טכניקה זו היא נוחה למגוון רחב של יישומים.

אור גומל ומיקרוסקופי אלקטרונים (קלם) ככלי למדמיינים מולקולות Microinjected והיעדים האיקריוטים תת סלולריים


The eukaryotic cell relies on complex, highly regulated, and functionally distinct membrane bound compartments that preserve a biochemical polarity ...

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Biology

Correlative Light and Electron Microscopy (CLEM) as a Tool to Visualize Microinjected Molecules and their Eukaryotic Sub-cellular Targets

19.0K Views.  University of Texas Southwestern Medical Center. טכניקת קלם הותאמה לנתח מורפולוגיה ultrastructural של קרומים, האברונים, ומבני subcellular מושפעים מולקולות microinjected. שיטה זו משלבת טכניקות רבות העצמה של המיקרומניפולציה / microinjection, מיקרוסקופיה confocal ניאון, וכן במיקרוסקופ אלקטרונים כדי לאפשר מילימטר לרזולוציה רבה ננומטר. טכניקה...

Video: Correlative Light and Electron Microscopy CLEM as a Tool to Visualize Microinjected Molecules and their Eukaryotic Sub-cellular Targets

Electroantennographic Bioassay as a Screening Tool for Host Plant Volatiles

Plant volatiles play an important role in plant-insect interactions. Herbivorous insects use plant volatiles, known as kairomones, to locate their host plant.1,2 When a host plant is an important agronomic commodity feeding damage by insect pests can inflict serious economic losses to growers. Accordingly, kairomones can be used as attractants to lure or confuse these insects and, thus, offer an environmentally friendly alternative to pesticides for insect control.3 Unfortunately, plants can emit a vast number volatiles with varying compositions and ratios of emissions dependent upon the phenology of the commodity or the time of day. This makes identification of biologically active components or blends of volatile components an arduous process. To help identify the bioactive components of host plant volatile emissions we employ the laboratory-based screening bioassay electroantennography (EAG). EAG is an effective tool to evaluate and record electrophysiologically the olfactory responses of an insect via their antennal receptors. The EAG screening process can help reduce the number of volatiles tested to identify promising bioactive components. However, EAG bioassays only provide information about activation of receptors. It does not provide information about the type of insect behavior the compound elicits; which could be as an attractant, repellent or other type of behavioral response. Volatiles eliciting a significant response by EAG, relative to an appropriate positive control, are typically taken on to further testing of behavioral responses of the insect pest. The experimental design presented will detail the methodology employed to screen almond-based host plant volatiles4,5 by measurement of the electrophysiological antennal responses of an adult insect pest navel orangeworm (Amyelois transitella) to single components and simple blends of components via EAG bioassay. The method utilizes two excised antennae placed across a "fork" electrode holder. The protocol demonstrated here presents a rapid, high-throughput standardized method for screening volatiles. Each volatile is at a set, constant amount as to standardize the stimulus level and thus allow antennal responses to be indicative of the relative chemoreceptivity. The negative control helps eliminate the electrophysiological response to both residual solvent and mechanical force of the puff. The positive control (in this instance acetophenone) is a single compound that has elicited a consistent response from male and female navel orangeworm (NOW) moth. An additional semiochemical standard that provides consistent response and is used for bioassay studies with the male NOW moth is (Z,Z)-11,13-hexdecadienal, an aldehyde component from the female-produced sex pheromone.6-8

A method to rapidly screen host plant volatiles by measurement of the electrophysiological response of adult navel orangeworm (Amyelois transitella) antennae to single components and blends via electroantennographic analysis is demonstrated.

המבדק Electroantennographic ככלי מיון עבור נדיפים צמחים מארח

Plant volatiles play an important role in plant-insect interactions. Herbivorous insects use plant volatiles, known as kairomones, to locate their host ...

Using SecM Arrest Sequence as a Tool to Isolate Ribosome Bound Polypeptides

Extensive research has provided ample evidences suggesting that protein folding in the cell is a co-translational process1-5. However, the exact pathway that polypeptide chain follows during co-translational folding to achieve its functional form is still an enigma. In order to understand this process and to determine the exact conformation of the co-translational folding intermediates, it is essential to develop techniques that allow the isolation of RNCs carrying nascent chains of predetermined sizes to allow their further structural analysis.
SecM (secretion monitor) is a 170 amino acid E. coli protein that regulates expression of the downstream SecA (secretion driving) ATPase in the secM-secA operon6. Nakatogawa and Ito originally found that a 17 amino acid long sequence (150-FSTPVWISQAQGIRAGP-166) in the C-terminal region of the SecM protein is sufficient and necessary to cause stalling of SecM elongation at Gly165, thereby producing peptidyl-glycyl-tRNA stably bound to the ribosomal P-site7-9. More importantly, it was found that this 17 amino acid long sequence can be fused to the C-terminus of virtually any full-length and/or truncated protein thus allowing the production of RNCs carrying nascent chains of predetermined sizes7. Thus, when fused or inserted into the target protein, SecM stalling sequence produces arrest of the polypeptide chain elongation and generates stable RNCs both in vivo in E. coli cells and in vitro in a cell-free system. Sucrose gradient centrifugation is further utilized to isolate RNCs.
The isolated RNCs can be used to analyze structural and functional features of the co-translational folding intermediates. Recently, this technique has been successfully used to gain insights into the structure of several ribosome bound nascent chains10,11. Here we describe the isolation of bovine Gamma-B Crystallin RNCs fused to SecM and generated in an in vitro translation system.

We describe here a technique that is now routinely used to isolate stably bound ribosome nascent chain complexes (RNCs). This technique takes advantage of the discovery that a 17 amino acid long SecM "arrest sequence" can halt translation elongation in a prokaryotic (E. coli) system, when inserted into (or fused to the C-terminus) of virtually any protein.

באמצעות רצף מעצר SecM ככלי לבודד פוליפפטידים כרוכים הריבוזום

Extensive research has provided ample evidences suggesting that protein folding in the cell is a co-translational process1-5. However, the exact pathway ...

In vivo Clonal Tracking of Hematopoietic Stem and Progenitor Cells Marked by Five Fluorescent Proteins using Confocal and Multiphoton Microscopy

We developed and validated a fluorescent marking methodology for clonal tracking of hematopoietic stem and progenitor cells (HSPCs) with high spatial and temporal resolution to study in vivo hematopoiesis using the murine bone marrow transplant experimental model. Genetic combinatorial marking using lentiviral vectors encoding fluorescent proteins (FPs) enabled cell fate mapping through advanced microscopy imaging. Vectors encoding five different FPs: Cerulean, EGFP, Venus, tdTomato, and mCherry were used to concurrently transduce HSPCs, creating a diverse palette of color marked cells. Imaging using confocal/two-photon hybrid microscopy enables simultaneous high resolution assessment of uniquely marked cells and their progeny in conjunction with structural components of the tissues. Volumetric analyses over large areas reveal that spectrally coded HSPC-derived cells can be detected non-invasively in various intact tissues, including the bone marrow (BM), for extensive periods of time following transplantation. Live studies combining video-rate multiphoton and confocal time-lapse imaging in 4D demonstrate the possibility of dynamic cellular and clonal tracking in a quantitative manner.

In vivo Clonal Tracking of Hematopoietic Stem and Progenitor Cells Marked by Five Fluorescent Proteins using Confocal and Multiphoton Microscopy

Combinatorial 5 fluorescent proteins marking of hematopoietic stem and progenitor cells allows in vivo clonal tracking via confocal and two-photon microscopy, providing insights into bone marrow hematopoietic architecture during regeneration. This method allows non-invasive fate mapping of spectrally-coded HSPCs-derived cells in intact tissues for extensive periods of time following transplantation.

במשובט מעקב vivo של גזע hematopoietic ובתאים המסומנים על ידי חמישה חלבונים ניאון באמצעות Confocal וmultiphoton מיקרוסקופית

We developed and validated a fluorescent marking methodology for clonal tracking of hematopoietic stem and progenitor cells (HSPCs) with high spatial and ...

Correlative Confocal and 3D Electron Microscopy of a Specific Sensory Cell

Delineation of a cell&#8217;s ultrastructure is important for understanding its function. This can be a daunting project for rare cell types diffused throughout tissues made of diverse cell types, such as enteroendocrine cells of the intestinal epithelium. These gastrointestinal sensors of food and bacteria have been difficult to study because they are dispersed among other epithelial cells at a ratio of 1:1,000. Recently, transgenic reporter mice have been generated to identify enteroendocrine cells by means of fluorescence. One of those is the peptide YY-GFP mouse. Using this mouse, we developed a method to correlate confocal and serial block-face scanning electron microscopy. We named the method cocem3D and applied it to identify a specific enteroendocrine cell in tissue and unveil the cell&#8217;s ultrastructure in 3D. The resolution of cocem3D is sufficient to identify organelles as small as secretory vesicles and to distinguish cell membranes for volume rendering. Cocem3D can be easily adapted to study the 3D ultrastructure of other specific cell types in their native tissue.

Here, we introduce a method, cocem3D, to unveil the ultrastructure of a specific cell in its native tissue by bridging confocal and serial block-face scanning electron microscopy.

מתאם Confocal ו3D מיקרוסקופית אלקטרונים של תא חושי ספציפי

Delineation of a cell&#8217;s ultrastructure is important for understanding its function. This can be a daunting project for rare cell types diffused ...

Scanning Electron Microscopy of Macerated Tissue to Visualize the Extracellular Matrix

Fibrosis is a component of all forms of heart disease regardless of etiology, and while much progress has been made in the field of cardiac matrix biology, there are still major gaps related to how the matrix is formed, how physiological and pathological remodeling differ, and most importantly how matrix dynamics might be manipulated to promote healing and inhibit fibrosis. There is currently no treatment option for controlling, preventing, or reversing cardiac fibrosis. Part of the reason is likely the sheer complexity of cardiac scar formation, such as occurs after myocardial infarction to immediately replace dead or dying cardiomyocytes. The extracellular matrix itself participates in remodeling by activating resident cells and also by helping to guide infiltrating cells to the defunct lesion. The matrix is also a storage locker of sorts for matricellular proteins that are crucial to normal matrix turnover, as well as fibrotic signaling. The matrix has additionally been demonstrated to play an electromechanical role in cardiac tissue. Most techniques for assessing fibrosis are not qualitative in nature, but rather provide quantitative results that are useful for comparing two groups but that do not provide information related to the underlying matrix structure. Highlighted here is a technique for visualizing cardiac matrix ultrastructure. Scanning electron microscopy of decellularized heart tissue reveals striking differences in structure that might otherwise be missed using traditional quantitative research methods.

Shown here is a method for visualizing extracellular matrix ultrastructure in decellularized cardiac tissues.

מיקרוסקופ אלקטרוני סורק של רקמות macerated לדמיין את תאי מטריקס

Fibrosis is a component of all forms of heart disease regardless of etiology, and while much progress has been made in the field of cardiac matrix ...

Preparation of Prokaryotic and Eukaryotic Organisms Using Chemical Drying for Morphological Analysis in Scanning Electron Microscopy (SEM)

Scanning electron microscopy (SEM) is a widely available technique that has been applied to study biological specimens ranging from individual proteins to cells, tissues, organelles, and even whole organisms. This protocol focuses on two chemical drying methods, hexamethyldisilazane (HMDS) and t-butyl alcohol (TBA), and their application to imaging of both prokaryotic and eukaryotic organisms using SEM. In this article, we describe how to fix, wash, dehydrate, dry, mount, sputter coat, and image three types of organisms: cyanobacteria (Toxifilum mysidocida, Golenkina sp., and an unknown sp.), two euglenoids from the genus Monomorphina (M. aenigmatica and M. pseudopyrum), and the fruit fly (Drosophila melanogaster). The purpose of this protocol is to describe a fast, inexpensive, and simple method to obtain detailed information about the structure, size, and surface characteristics of specimens that can be broadly applied to a large range of organisms for morphological assessment. Successful completion of this protocol will allow others to use SEM to visualize samples by applying these techniques to their system.

Preparation of Prokaryotic and Eukaryotic Organisms Using Chemical Drying for Morphological Analysis in Scanning Electron Microscopy SEM

SEM analysis is an effective method to aid in species identification or phenotypic discrimination. This protocol describes the methods for examining specific morphological details of three representative types of organisms and would be broadly applicable to examining features of many organismal and tissue types.

הכנה של אורגניזמים Prokaryotic ו האיקריוטים באמצעות ייבוש כימיים עבור ניתוח מורפולוגי סריקה מיקרוסקופ אלקטרונים (SEM)

Scanning electron microscopy (SEM) is a widely available technique that has been applied to study biological specimens ranging from individual proteins to ...

Biological Sample Preparation by High-pressure Freezing, Microwave-assisted Contrast Enhancement, and Minimal Resin Embedding for Volume Imaging

The described sample preparation technique is designed to combine the best quality of ultrastructural preservation with the most suitable contrast for the imaging modality in a focused ion beam scanning electron microscope (FIB-SEM), which is used to obtain stacks of sequential images for 3D reconstruction and modelling. High-pressure freezing (HPF) allows close to native structural preservation, but the subsequent freeze substitution often does not provide sufficient contrast, especially for a bigger specimen, which is needed for high-quality imaging in the SEM required for 3D reconstruction. Therefore, in this protocol, after the freeze substitution, additional contrasting steps are carried out at room temperature. Although these steps are performed in a microwave, it is also possible to follow traditional bench processing, which requires longer incubation times.The subsequent embedding in minimal amounts of resin allows for faster and more precise targeting and preparation inside the FIB-SEM. This protocol is especially useful for samples that require preparation by high-pressure freezing for a reliable ultrastructural preservation but do not gain enough contrast during the freeze substitution for volume imaging using FIB-SEM. In combination with the minimal resin embedding, this protocol provides an efficient workflow for the acquisition of high-quality volume data.

Here we present a protocol for combining two sample processing techniques, high-pressure freezing and microwave-assisted sample processing, followed by minimal resin embedding for acquiring data with a focused ion beam scanning electron microscope (FIB-SEM). This is demonstrated using a mouse tibial nerve sample and Caenorhabditis elegans.

הכנת הדוגמא ביולוגית על ידי הקפאת בלחץ גבוה, שיפור ניגודיות בסיוע מיקרוגל, ושרף מינימלי הטמעה של אמצעי הדמיה

The described sample preparation technique is designed to combine the best quality of ultrastructural preservation with the most suitable contrast for the ...

Cryo-Electron Microscopic Grid Preparation for Time-Resolved Studies using a Novel Robotic System, Spotiton

The capture of short-lived molecular states triggered by the early encounter of two or more interacting particles continues to be an experimental challenge of great interest to the field of cryo-electron microscopy (cryo-EM). A few methodological strategies have been developed that support these &#34;time-resolved&#34; studies, one of which, Spotiton-a novel robotic system-combines the dispensing of picoliter-sized sample droplets with precise temporal and spatial control. The time-resolved Spotiton workflow offers a uniquely efficient approach to interrogate early structural rearrangements from minimal sample volume. Fired from independently controlled piezoelectric dispensers, two samples land and rapidly mix on a nanowire EM grid as it plunges toward the cryogen. Potentially hundreds of grids can be prepared in rapid succession from only a few microliters of a sample. Here, a detailed step-by-step protocol of the operation of the Spotiton system is presented with a focus on troubleshooting specific problems that arise during grid preparation.

The protocol presented here describes the use of Spotiton, a novel robotic system, to deliver two samples of interest onto a self-wicking, nanowire grid that mix for a minimum of 90 ms prior to vitrification in liquid cryogen.

הכנת רשת מיקרוסקופית קריו-אלקטרון למחקרים שנפתרו בזמן באמצעות מערכת רובוטית חדשנית, Spotiton

The capture of short-lived molecular states triggered by the early encounter of two or more interacting particles continues to be an experimental ...

Ultrastructural Localization of Endogenous LC3 by On-Section Correlative Light-Electron Microscopy

The visualization of autophagic organelles at the ultrastructural level by electron microscopy (EM) is essential to establish their identity and reveal details that are important for understanding the autophagic process. However, EM methods often lack molecular information, obstructing the correlation of ultrastructural information obtained by EM to fluorescence microscopy-based localization of specific autophagy proteins. Furthermore, the rarity of autophagosomes in unaltered cellular conditions hampers investigation by EM, which requires high magnification, and hence provides a limited field of view.
In answer to both challenges, an on-section correlative light-electron microscopy (CLEM) method based on fluorescent labeling was applied to correlate a common autophagosomal marker, LC3, to EM ultrastructure. The method was used to rapidly screen cells in fluorescence microscopy for LC3 labeling in combination with other relevant markers. Subsequently, the underlying ultrastructural features of selected LC3-labeled spots were identified by CLEM. The method was applied to starved cells without adding inhibitors of lysosomal acidification.
In these conditions, LC3 was found predominantly on autophagosomes and rarely in autolysosomes, in which LC3 is rapidly degraded. These data show both the feasibility and sensitivity of this approach, demonstrating that CLEM can be used to provide ultrastructural insights on LC3-mediated autophagy in native conditions-without drug treatments or genetic alterations. Overall, this method presents a valuable tool for ultrastructural localization studies of autophagy proteins and other scarce antigens by bridging light microscopy to EM data.

Here, we present a protocol for optimized on-section correlative light-electron microscopy based on endogenous, fluorescent labeling as a tool to investigate the localization of rare proteins in relation to cellular ultrastructure. The power of this approach is demonstrated by ultrastructural localization of endogenous LC3 in starved cells without Bafilomycin treatment.

לוקליזציה אולטרה-מבנית של LC3 אנדוגני על ידי מיקרוסקופ אור-אלקטרונים קורלטיבי בחתך

The visualization of autophagic organelles at the ultrastructural level by electron microscopy (EM) is essential to establish their identity and reveal ...

פרוטוקול חדשני לשימור פלואורסצנטי ואולטרה-מבנה בו זמנית

Epon Post Embedding Correlative Light and Electron Microscopy

Correlative light and electron microscopy (CLEM) is a comprehensive microscopy that combines the localization information provided by fluorescence microscopy (FM) and the context of cellular ultrastructure acquired by electron microscopy (EM). CLEM is a trade-off between fluorescence and ultrastructure, and usually, ultrastructure compromises fluorescence. Compared with other hydrophilic embedding resins, such as glycidyl methacrylate, HM20, or K4M, Epon is superior in ultrastructure preservation and sectioning properties. Previously, we had demonstrated that mEosEM can survive osmium tetroxide fixation and Epon embedding. Using mEosEM, we achieved, for the first time, Epon post embedding CLEM, which maintains the fluorescence and the ultrastructure simultaneously. Here, we provide step-by-step details about the EM sample preparation, the FM imaging, the EM imaging, and the image alignment. We also improve the procedures for identifying the same cell imaged by FM imaging during the EM imaging and detail the registration between the FM and EM images. We believe one can easily achieve Epon post embedding correlative light and electron microscopy following this new protocol in traditional EM facilities.

מחבר זרקור: התקדמות באור מתאם ומיקרוסקופ אלקטרונים עם שימור חלבון פלואורסצנטי

We present a detailed protocol for Epon post-embedding correlative light and electron microscopy using a fluorescent protein called mScarlet. This method can maintain the fluorescence and the ultrastructure simultaneously. This technique is amenable to a wide variety of biological applications.