We would like to acknowledge Dr. Thomas Rademacher, Alexander Boes and Veronique Bei&#223; for providing the transgenic tobacco seeds, and Ibrahim Al Amedi for cultivating the tobacco plants. The authors wish to thank Dr. Richard M. Twyman for editorial assistance as well as G&#252;ven Edg&#252; for providing the MSP1-19 reference. This work was funded in part by the European Research Council Advanced Grant ''Future-Pharma'', proposal number 269110, the Fraunhofer-Zukunftsstiftung (Fraunhofer Future Foundation) and Fraunhofer-Gesellschaft Internal Programs under Grant No. Attract 125-600164.

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שלוש השיטות עבור משקעים חום המתואר לעיל ניתן להסיר ביעילות HCPs טבק לפני כל צעד טיהור chromatographic 16,17. הם משלימים אסטראטגי אחרים שמטרתן להגדיל טוהר מוצר ראשוני, למשל, guttation 29, rhizosecretion 30 או צנטריפוגלי חילוץ 31,32, שכולן מוגבלי חלבונים מופרשים. עם זא?...

מערכות בריאות מודרניות תלויות יותר ויותר על חלבונים ביולוגיים 1. הפקת חלבונים אלה בצמחים יש יתרון בגלל הנטל הפתוגן נמוך מדרוג גבוה יותר בהשוואה למערכות ביטוי קונבנציונאלי 2-4. עם זאת, העיבוד במורד הזרם (DSP) של תרופות צמחיות יכול להיות מאתגר, מכיוון שתהליך החילוץ משבש לגרום לניטל חלקיקים גבוה, עם turbidities העולה על 5,000 יחידות עכירות nephelometric (NTUs), וחלבון תא מארח (HCP) ריכוזים לעתים קרובות עולים על 95 % [מ &#39;/ מ&#39;] 5,6. נהלי הבהרה משוכללים נדרשים להסיר התפזרו חלקיקים 7-9, אבל ציוד כרומטוגרפיה הוא פחות יקר לפעול במצב לאגד-ו-elute במהלך ההתאוששות ראשונית של מוצר אם יש שלב מוקדם להסרת יעיל של HCPs 10,11. זו יכולה להיות מושגת גם על ידי מזרז חלבון המטרה באמצעות flocculנמלים 12 או pH נמוך 13,14, כמו גם על ידי גורם HCPs לצבור. ההצטברות סלקטיבית של ribulose-1,5-bisphosphate carboxylase / oxygenase (RuBisCO), את HCP הנפוץ ביותר בצמחים ירוקים כגון טבק (טבק), ניתן לקדם באמצעות הוספת פוליאתילן גליקול 15, אבל זה יקר עולה בקנה אחד עם גדול ייצור -scale. עיבוד תרמי הוכח לפגל משקע יותר מ -95% של HCPs טבק, בעוד מועמדי חיסון חלבון מלריה כגון Vax8 להישאר יציבים בתמיסה 16-18. שלוש גישות שונות שימשו כדי להשיג את המשקעים הנגרמת בלהט HCPs טבק: (i) הלבנה, כלומר, טבילה של עלים שלמים נוזל חם, (ii) בטמפרטורה מבוקרת עוררה כלי, וכן (iii) מחליף חום ( איור 1) 16. לקבלת עלים שלמים, לבנה השיג את המשקעים המהירים ויעילים של HCPs והיה גם קלבהיקף של עד ועומד בקנה אחד עם תהליכי ייצור בקנה מידה גדול הקיימים הכוללים צעד ראשון לשטוף את ביומסה במפעל 19. לעומת זאת, כלי בקרת טמפרטורה כבר זמין בתהליכים מסוימים וניתן להשתמש בו לטיפול התרמי של תמציות צמחים 20, אבל מדרגיות אנרגית קצב העברה שלהם מוגבלות בגלל היחס שטחו פן לנפח של הטנקים מצטמצם בהדרגה הופך מתאים בקנה מידה תהליך. מחליף חום הוא אלטרנטיבה מוגדרת היטב מבחינה טכנית מחוממת כלי עוררה אבל דורש שפע של חימום ומדיה קירור, למשל, קיטור ומים קרים, כמו גם ספיקה בחוזקה מבוקרת ומותאמת הגיאומטריה המחליפה חום נכסי מדיה, למשל., קיבולת החום הסגולית. מאמר זה מראה כיצד כל שלוש שיטות יכולות לשמש עבור הממטרים החומים הנגרמת של HCPs הטבק, HCPs צמח בכלל. הקמה והפעלה של EACשיטת h במעבדה הגדרה שניתן להשתמש בהם כדי להעריך את מידת התאמתם תהליכים בקנה מידה גדול יותר. האתגר העיקרי הוא לזהות מודלים בקנה מידה למטה נאותים ותנאי פועל עבור כל פעולה דומה ההתקנים ותנאי שימוש במהלך תהליך ייצור בקנה מידה. הנתונים המוצגים כאן מתייחסים ניסויים שנערכו עם צמחי טבק מהונדסים מבטא מועמד חיסון למלריה Vax8 ו חלבון פלואורסצנטי DsRed 16, אבל השיטה גם יושמה בהצלחת נ צמחי benthamiana לבטא חלבונים ביולוגיים אחרים זמן 21. עיצוב-של-ניסויים (DOE) להתקרב 22 יכול להקל על פיתוח תהליך, flocculants 23 יכול גם להיות מועיל בהקשר זה כפי שתואר לעיל 8. ההבדל העיקרי בין הלבנה, כלי מחומם מחליפי חום הוא הלבנה מוחלת על עלים שלמים מוקדם בתהליך ואילו otשלה מוחלים תמציות צמחים (איור 1). <img alt="איור 1" src="/files/ftp_upload/54343/54343fig1.jpg" /> איור 1:. תהליך Scheme הזרימה הממחיש את היישום בשלוש שיטות שונות עבור משקעי חום הטבק HCP החומר הצמחי נשטף הומוגני לפני ההבהרה וטיהור. הציוד עבור השלב הלבן (אדום) ניתן להוסיף בקלות על המכונות הקיימות. לעומת זאת, מתוך כלי בחש (כתומה) ובמיוחד מחליף חום (כחול) דורש אחד או מספר התקנים נוספים צינורות. <a href="https://www.jove.com/files/ftp_upload/54343/54343fig1large.jpg" target="_blank">אנא לחץ כאן כדי לצפות בגרסה גדולה יותר של דמות זו.</a>

<table border="0" cellpadding="0" cellspacing="0" width="1026">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">2100P Portable Turbidimeter</td>
			<td style="width:195px;">Hach</td>
			<td style="width:119px;">4650000</td>
			<td style="width:352px;">Turbidimeter</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Amine Coupling Kit</td>
			<td style="width:195px;">GE Healthcare</td>
			<td style="width:119px;">BR100050&#160;</td>
			<td>SPR chip coupling kit</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Autoclaving basket</td>
			<td style="width:195px;">Nalgene</td>
			<td style="width:119px;">6917-0230</td>
			<td>Basket for leaf blanching</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Biacore T200</td>
			<td style="width:195px;">GE Healthcare</td>
			<td style="width:119px;">28-9750-01</td>
			<td>SPR device</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Bio Cell Analyser BCA 003 R&#38;D with 3D ORM</td>
			<td style="width:195px;">Sequip</td>
			<td style="width:119px;">n.a.</td>
			<td>Particle size analyzer</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Blender</td>
			<td style="width:195px;">Waring</td>
			<td style="width:119px;">800EG</td>
			<td>Blender</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">BP-410</td>
			<td style="width:195px;">Furh</td>
			<td style="width:119px;">2632410001</td>
			<td>Bag filter</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Centrifuge 5415D</td>
			<td style="width:195px;">Eppendorf</td>
			<td style="width:119px;">5424 000.410</td>
			<td>Centrifuge</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Centrifuge tube 15 mL</td>
			<td style="width:195px;">Labomedic</td>
			<td style="width:119px;">2017106</td>
			<td>Reaction tube</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Centrifuge tube 50 mL self-standing</td>
			<td style="width:195px;">Labomedic</td>
			<td style="width:119px;">1110504</td>
			<td>Reaction tube</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">CM5 chip</td>
			<td style="width:195px;">GE Healthcare</td>
			<td style="width:119px;">BR100012&#160;</td>
			<td>Chip for SPR measurements</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Cuvette 10x10x45</td>
			<td style="width:195px;">Sarsted</td>
			<td style="width:119px;">67.754</td>
			<td>Cuvette for Zetasizer Nano ZS</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Design-Expert(R) 8</td>
			<td style="width:195px;">Stat-Ease, Inc.</td>
			<td style="width:119px;">n.a.</td>
			<td>DoE software</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Disodium phosphate</td>
			<td style="width:195px;">Carl Roth GmbH</td>
			<td style="width:119px;">&#160;4984.3&#160;</td>
			<td>Media component</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Ferty 2 Mega</td>
			<td style="width:195px;">Kammlott</td>
			<td style="width:119px;">5.220072</td>
			<td>Fertilizer</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Forma -86C ULT freezer</td>
			<td style="width:195px;">ThermoFisher</td>
			<td style="width:119px;">88400</td>
			<td>Freezer</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Greenhouse</td>
			<td style="width:195px;">n.a.</td>
			<td style="width:119px;">n.a.</td>
			<td>For plant cultivation</td>
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		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Grodan Rockwool Cubes 10x10cm</td>
			<td style="width:195px;">Grodan</td>
			<td style="width:119px;">102446</td>
			<td>Rockwool block</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Twentey-loop heat exchanger (4.8 m length)</td>
			<td style="width:195px;">n.a. (custom design)</td>
			<td style="width:119px;">n.a.</td>
			<td>Heat exchanger</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">HEPES</td>
			<td style="width:195px;">Carl Roth GmbH</td>
			<td style="width:119px;">9105.3</td>
			<td>Media component</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">K200P 60D</td>
			<td style="width:195px;">Pall</td>
			<td style="width:119px;">5302303</td>
			<td>Depth filter layer</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">KS50P 60D</td>
			<td style="width:195px;">Pall</td>
			<td style="width:119px;">B12486</td>
			<td>Depth filter layer</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Lauda E300</td>
			<td style="width:195px;">Lauda Dr Wobser GmbH</td>
			<td style="width:119px;">Z90010</td>
			<td>Water bath thermostat</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">L/S 24</td>
			<td style="width:195px;">Masterflex</td>
			<td style="width:119px;">SN-06508-24</td>
			<td>Tubing</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:360px;">mAb 5.2</td>
			<td style="width:195px;">American Type Culture Collection</td>
			<td style="width:119px;">HB-9148</td>
			<td>Vax8 specific antibody</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Masterflex L/S</td>
			<td style="width:195px;">Masterflex</td>
			<td style="width:119px;">HV-77921-75</td>
			<td>Peristaltic pump</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Miracloth</td>
			<td style="width:195px;">Labomedic</td>
			<td style="width:119px;">475855-1R</td>
			<td>Filter cloth</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">MultiLine Multi 3410 IDS</td>
			<td style="width:195px;">WTW</td>
			<td style="width:119px;">WTW_2020</td>
			<td>pH meter / conductivity meter</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Osram cool white 36 W</td>
			<td style="width:195px;">Osram</td>
			<td style="width:119px;">4930440</td>
			<td>Light source</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Phytotron</td>
			<td style="width:195px;">Ilka Zell</td>
			<td style="width:119px;">n.a.</td>
			<td>For plant cultivation</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Sodium disulfit</td>
			<td style="width:195px;">Carl Roth GmbH</td>
			<td style="width:119px;">8554.1</td>
			<td>Media component</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Sodium chloride</td>
			<td style="width:195px;">Carl Roth GmbH</td>
			<td style="width:119px;">P029.2</td>
			<td>Media component</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:360px;">Stainless-steel vessel; 0.7-kg 2.0-L; height 180 mm; diameter 120 mm</td>
			<td style="width:195px;">n.a. (custom design)</td>
			<td style="width:119px;">n.a.</td>
			<td>Container for heat precipitation</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Synergy HT</td>
			<td style="width:195px;">BioTek</td>
			<td style="width:119px;">SIAFRT</td>
			<td>Fluorescence and spectrometric plate reader</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">VelaPad 60</td>
			<td style="width:195px;">Pall</td>
			<td style="width:119px;">VP60G03KNH4</td>
			<td>Filter housing</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Zetasizer Nano ZS</td>
			<td style="width:195px;">Malvern</td>
			<td style="width:119px;">ZEN3600</td>
			<td>DLS particle size distribution measurement</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Zetasizer Software v7.11</td>
			<td style="width:195px;">Malvern</td>
			<td style="width:119px;">n.a.</td>
			<td>Software to operate the Zetasizer Nano ZS device</td>
		</tr>
	</tbody>
</table>

comparison of tobacco host cell protein removal methods by blanching intact plants or by heat treatment of extracts

צמחים לא רק לספק מזון, מזון וחומר גלם עבור בני אדם, אלא גם פותחו כמערכת ייצור חסכונית עבור חלבונים הביו-פרמצבטיקה, כגון נוגדנים, מועמדי חיסון ואנזימים. חייבים להיות מטוהרים אלה מן ביומסה במפעל אבל צעדים כרומטוגרפיה הם הפריעו ידי הריכוזים הגבוהים של חלבוני תא מארח (HCPs) תמציות צמחים. עם זאת, רוב HCPs לצבור באופן בלתי הפיך בטמפרטורות מעל 60 מעלות צלזיוס הקלת הטיהור הבאה של חלבון המטרה. הנה, שלוש שיטות מוצגות כדי להשיג את המשקעים בלהט HCPs טבק או שלמי עלים או תמציות. מבצע לבנת עלים שלמים ניתן לשלב בקלות לתוך תהליכים קיימים אך עשויה להיות השפעה שלילית על צעדי סינון הבאים. ההפך הוא נכון עבור משקעים חומים של תמציות עלו בתוך כלי בחש, אשר יכול לשפר את הביצועים של פעולות במורד זרם אמנם עם שינויים משמעותיים בעיצוב מכשור הטכנולוגי, כגוןגיאומטרית homogenizer. לבסוף, התקנה מחליפה חום מאופיין גם מבחינת תנאי העברת חום קל מידה, אבל ניקוי יכול להיות קשה ולא תיתכן השפעה שלילית על יכולת סינון. העיצוב-של-ניסויי הגישה יכולה לשמש כדי לזהות את הפרמטרים של תהליך הרלוונטיים ביותר משפיעי הסרת HCP והתאוששות מוצר. זה מקל על היישום של כל שיטה בפלטפורמות ביטוי אחרות וזיהוי של השיטה המתאימה ביותר עבור אסטרטגיה לטיהור נתונה.

ממטרים חומים של חלבוני תא מארח טבק ידי לבן ההליך הלבנה בסעיף 2. שימש בהצלחה כדי לזרז HCPs מטבק עלים עם 70 מעלות צלזיוס, דבר שיפחית את TSP ידי 96 ± 1% (n = 3) בעודו מחלים עד 51% של חלבון המטרה Vax8, ובכך להגדיל שלה טוהר מ -0.1% ל -1.2% לפני ההפרדה chromatographic 16. ז?...

Watch this Scientific Journal Video about Comparison of Tobacco Host Cell Protein Removal Methods by Blanching Intact Plants or by Heat Treatment of Extracts at JoVE.com

Comparison of Tobacco Host Cell Protein Removal Methods by Blanching Intact Plants or by Heat Treatment of Extracts

שלושה חום שיטות ממטרים מוצגות ביעילות להסיר יותר מ -90% של חלבוני תא מארח (HCPs) מטבק תמציות לפני כל צעד טיהור אחר. המפעל HCPs לצבור באופן בלתי הפיך בטמפרטורות מעל 60 מעלות צלזיוס.

השוואת שיטות להסרת Cell חלבון מארח טבק ידי לבנת צמחים שלמים או על ידי טיפול בחום של תמציות

Plants not only provide food, feed and raw materials for humans, but have also been developed as an economical production system for biopharmaceutical ...

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Research

JoVE Journal

Biology

9.0K Views.  Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e. V..  שלושה חום שיטות ממטרים מוצגות ביעילות להסיר יותר מ -90% של חלבוני תא מארח (HCPs) מטבק תמציות לפני כל צעד טיהור אחר. המפעל HCPs לצבור באופן בלתי הפיך בטמפרטורות מעל 60 מעלות צלזיוס. 

Video: Comparison of Tobacco Host Cell Protein Removal Methods by Blanching Intact Plants or by Heat Treatment of Extracts

Derivation of Human Embryonic Stem Cells by Immunosurgery

The ability of human embryonic stem cells to self-renew and differentiate into all cell types of 
the body suggests that they hold great promise for both medical applications and as a research 
tool for addressing fundamental questions in development and disease. Here, we provide a 
concise, step-by-step protocol for the derivation of human embryonic stem cells from embryos 
by immunosurgical isolation of the inner cell mass. 


The ability of human embryonic stem cells to self-renew and differentiate into all cell types of 
the body suggests that they hold great promise for both medical applications and as a research 
tool for addressing fundamental questions in development and disease. Here, we provide a 
concise, step-by-step protocol for the derivation of human embryonic stem cells from embryos 
by immunosurgical isolation of the inner cell mass.

גזירת בתאי גזע עובריים אנושיים על ידי Immunosurgery

The ability of human embryonic stem cells to self-renew and differentiate into all cell types of 
the body suggests that they hold great promise for both ...

Preparation and Fractionation of Xenopus laevis Egg Extracts

Crude and fractionated Xenopus egg extracts can be used to provide ingredients for reconstituting cellular processes for morphological and biochemical analysis. Egg lysis and differential centrifugation are used to prepare the crude extract which in turn in used to prepare fractionated extracts and light membrane preparations.

Crude and fractionated Xenopus egg extracts can be used to provide ingredients for reconstituting cellular processes for morphological and biochemical analysis. Egg lysis and differential centrifugation are used to prepare the crude extract which in turn in used to prepare fractionated extracts and light membrane preparations.

הכנה ההיפוך חלוקה של Xenopus laevis ביצה תמציות

Crude and fractionated Xenopus egg extracts can be used to provide ingredients for reconstituting cellular processes for morphological and biochemical ...

Detection of Post-translational Modifications on Native Intact Nucleosomes by ELISA

The genome of eukaryotes exists as chromatin which contains both DNA and proteins. The fundamental unit of chromatin is the nucleosome, which contains 146 base pairs of DNA associated with two each of histones H2A, H2B, H3, and H41. The N-terminal tails of histones are rich in lysine and arginine and are modified post-transcriptionally by acetylation, methylation, and other post-translational modifications (PTMs). The PTM configuration of nucleosomes can affect the transcriptional activity of associated DNA, thus providing a mode of gene regulation that is epigenetic in nature 2,3. We developed a method called nucleosome ELISA (NU-ELISA) to quantitatively determine global PTM signatures of nucleosomes extracted from cells. NU-ELISA is more sensitive and quantitative than western blotting, and is useful to interrogate the epiproteomic state of specific cell types. This video journal article shows detailed procedures to perform NU-ELISA analysis.

Nucleosome ELISA (NU-ELISA) is a sensitive and quantitative method to detect global patterns of post-translational modifications in preparations of native, intact nucleosomes. These modifications include methylations, acetylations, and phosphorylations at specific histone amino acid residues, and hence NU-ELISA provides a global proteomic assay of the overall chromatin modification states of specific cell types.

איתור של פוסט translational שינויים על nucleosomes אינטקט Native ידי ELISA

The genome of eukaryotes exists as chromatin which contains both DNA and proteins. The fundamental unit of chromatin is the nucleosome, which contains 146 ...

The MultiBac Protein Complex Production Platform at the EMBL

Proteomics research revealed the impressive complexity of eukaryotic proteomes in unprecedented detail. It is now a commonly accepted notion that proteins in cells mostly exist not as isolated entities but exert their biological activity in association with many other proteins, in humans ten or more, forming assembly lines in the cell for most if not all vital functions.1,2 Knowledge of the function and architecture of these multiprotein assemblies requires their provision in superior quality and sufficient quantity for detailed analysis. The paucity of many protein complexes in cells, in particular in eukaryotes, prohibits their extraction from native sources, and necessitates recombinant production. The baculovirus expression vector system (BEVS) has proven to be particularly useful for producing eukaryotic proteins, the activity of which often relies on post-translational processing that other commonly used expression systems often cannot support.3 BEVS use a recombinant baculovirus into which the gene of interest was inserted to infect insect cell cultures which in turn produce the protein of choice. MultiBac is a BEVS that has been particularly tailored for the production of eukaryotic protein complexes that contain many subunits.4 A vital prerequisite for efficient production of proteins and their complexes are robust protocols for all steps involved in an expression experiment that ideally can be implemented as standard operating procedures (SOPs) and followed also by non-specialist users with comparative ease. The MultiBac platform at the European Molecular Biology Laboratory (EMBL) uses SOPs for all steps involved in a multiprotein complex expression experiment, starting from insertion of the genes into an engineered baculoviral genome optimized for heterologous protein production properties to small-scale analysis of the protein specimens produced.5-8 The platform is installed in an open-access mode at EMBL Grenoble and has supported many scientists from academia and industry to accelerate protein complex research projects.

Protein complexes catalyze key cellular functions. Detailed functional and structural characterization of many essential complexes requires recombinant production. MultiBac is a baculovirus/insect cell system particularly tailored for expressing eukaryotic proteins and their complexes. MultiBac was implemented as an open-access platform, and standard operating procedures developed to maximize its utility.

פלטפורמת הפקת MultiBac החלבון המורכבת בEMBL

Proteomics  research revealed the impressive complexity of eukaryotic proteomes in  unprecedented detail. It is now a commonly accepted notion that ...

Protein-protein Interactions Visualized by Bimolecular Fluorescence Complementation in Tobacco Protoplasts and Leaves

Many proteins interact transiently with other proteins or are integrated into multi-protein complexes to perform their biological function. Bimolecular fluorescence complementation (BiFC) is an in vivo method to monitor such interactions in plant cells. In the presented protocol the investigated candidate proteins are fused to complementary halves of fluorescent proteins and the respective constructs are introduced into plant cells via agrobacterium-mediated transformation. Subsequently, the proteins are transiently expressed in tobacco leaves and the restored fluorescent signals can be detected with a confocal laser scanning microscope in the intact cells. This allows not only visualization of the interaction itself, but also the subcellular localization of the protein complexes can be determined. For this purpose, marker genes containing a fluorescent tag can be coexpressed along with the BiFC constructs, thus visualizing cellular structures such as the endoplasmic reticulum, mitochondria, the Golgi apparatus or the plasma membrane. The fluorescent signal can be monitored either directly in epidermal leaf cells or in single protoplasts, which can be easily isolated from the transformed tobacco leaves. BiFC is ideally suited to study protein-protein interactions in their natural surroundings within the living cell. However, it has to be considered that the expression has to be driven by strong promoters and that the interaction partners are modified due to fusion of the relatively large fluorescence tags, which might interfere with the interaction mechanism. Nevertheless, BiFC is an excellent complementary approach to other commonly applied methods investigating protein-protein interactions, such as coimmunoprecipitation, in vitro pull-down assays or yeast-two-hybrid experiments.

Formation of protein complexes in vivo can be visualized by bimolecular fluorescence complementation. Interaction partners are fused to complementary parts of fluorescent tags and transiently expressed in tobacco leaves, resulting in a reconstituted fluorescent signal upon close proximity of the two proteins.

חלבונים אינטראקציות דמיינו ידי bimolecular הקרינה complementation בProtoplasts הטבק ועלים

Many proteins interact transiently with other proteins or are integrated into multi-protein complexes to perform their biological function. Bimolecular ...

In Vivo 4-Dimensional Tracking of Hematopoietic Stem and Progenitor Cells in Adult Mouse Calvarial Bone Marrow

Through a delicate balance between quiescence and proliferation, self renewal and production of differentiated progeny, hematopoietic stem cells (HSCs) maintain the turnover of all mature blood cell lineages. The coordination of the complex signals leading to specific HSC fates relies upon the interaction between HSCs and the intricate bone marrow microenvironment, which is still poorly understood[1-2].
We describe how by combining a newly developed specimen holder for stable animal positioning with multi-step confocal and two-photon in vivo imaging techniques, it is possible to obtain high-resolution 3D stacks containing HSPCs and their surrounding niches and to monitor them over time through multi-point time-lapse imaging. High definition imaging allows detecting ex vivo labeled hematopoietic stem and progenitor cells (HSPCs) residing within the bone marrow. Moreover, multi-point time-lapse 3D imaging, obtained with faster acquisition settings, provides accurate information about HSPC movement and the reciprocal interactions between HSPCs and stroma cells.
Tracking of HSPCs in relation to GFP positive osteoblastic cells is shown as an exemplary application of this method. This technique can be utilized to track any appropriately labeled hematopoietic or stromal cell of interest within the mouse calvarium bone marrow space.

In Vivo 4-Dimensional Tracking of Hematopoietic Stem and Progenitor Cells in Adult Mouse Calvarial Bone Marrow

The nature of the interactions between hematopoietic stem and progenitor cells (HSPCs) and bone marrow niches is poorly understood. Custom hardware modifications and a multi-step acquisition protocol allow the use of two-photon and confocal microscopy to image ex vivo labeled HSPCs homed within bone marrow areas, tracking interactions and movement.

במעקב 4 ממדי Vivo של תאי גזע ואבות היווצרות דם במבוגרי עכבר calvarial מח עצם

Through a delicate balance between quiescence and proliferation, self renewal and production of differentiated progeny, hematopoietic stem cells (HSCs) ...

Generation of Transgenic Hydra by Embryo Microinjection

As a member of the phylum Cnidaria, the sister group to all bilaterians, Hydra can shed light on fundamental biological processes shared among multicellular animals. Hydra is used as a model for the study of regeneration, pattern formation, and stem cells. However, research efforts have been hampered by lack of a reliable method for gene perturbations to study molecular function. The development of transgenic methods has revitalized the study of Hydra biology1. Transgenic Hydra allow for the tracking of live cells, sorting to yield pure cell populations for biochemical analysis, manipulation of gene function by knockdown and over-expression, and analysis of promoter function. Plasmid DNA injected into early stage embryos randomly integrates into the genome early in development. This results in hatchlings that express transgenes in patches of tissue in one or more of the three lineages (ectodermal epithelial, endodermal epithelial, or interstitial). The success rate of obtaining a hatchling with transgenic tissue is between 10% and 20%. Asexual propagation of the transgenic hatchling is used to establish a uniformly transgenic line in a particular lineage. Generating transgenic Hydra is surprisingly simple and robust, and here we describe a protocol that can be easily implemented at low cost.

Generation of Transgenic Hydra by Embryo Microinjection

Stably transgenic Hydra are made by microinjection of plasmid DNA into embryos followed by random genomic integration and asexual propagation to establish a uniform line. Transgenic Hydra are used to track cell movements, overexpress genes, study promoter function, or knock down gene expression using RNAi.

דור של הטרנסגניים<em&gt; הידרה</em&gt; על ידי Microinjection העובר

As a member of the phylum Cnidaria, the sister group to all bilaterians, Hydra can shed light on fundamental biological processes shared among ...

Fecal Glucocorticoid Analysis: Non-invasive Adrenal Monitoring in Equids

Adrenal activity can be assessed in the equine species by analysis of feces for corticosterone metabolites. During a potentially aversive situation, corticotrophin releasing hormone (CRH) is released from the hypothalamus in the brain. This stimulates the release of adrenocorticotrophic hormone (ACTH) from the pituitary gland, which in turn stimulates release of glucocorticoids from the adrenal gland. In horses the glucocorticoid corticosterone is responsible for several adaptations needed to support equine flight behaviour and subsequent removal from the aversive situation. Corticosterone metabolites can be detected in the feces of horses and assessment offers a non-invasive option to evaluate long term patterns of adrenal activity. Fecal assessment offers advantages over other techniques that monitor adrenal activity including blood plasma and saliva analysis. The non-invasive nature of the method avoids sampling stress which can confound results. It also allows the opportunity for repeated sampling over time and is ideal for studies in free ranging horses. This protocol describes the enzyme linked immunoassay (EIA) used to assess feces for corticosterone, in addition to the associated biochemical validation.

Adrenal activity can be assessed in the equine species by analysis of feces for corticosterone metabolites. The method offers a non-invasive option to assess long term patterns in both domestic and free ranging horses. This protocol describes the enzyme linked immunoassay involved and the associated biochemical validation.

ניתוח Glucocorticoid צואה: לא פולשני ניטור הכליה ב Equids

Adrenal activity can be assessed in the equine species by analysis of feces for corticosterone metabolites. During a potentially aversive situation, ...

DamID-seq: Genome-wide Mapping of Protein-DNA Interactions by High Throughput Sequencing of Adenine-methylated DNA Fragments

The DNA adenine methyltransferase identification (DamID) assay is a powerful method to detect protein-DNA interactions both locally and genome-wide. It is an alternative approach to chromatin immunoprecipitation (ChIP). An expressed fusion protein consisting of the protein of interest and the E. coli DNA adenine methyltransferase can methylate the adenine base in GATC motifs near the sites of protein-DNA interactions. Adenine-methylated DNA fragments can then be specifically amplified and detected. The original DamID assay detects the genomic locations of methylated DNA fragments by hybridization to DNA microarrays, which is limited by the availability of microarrays and the density of predetermined probes. In this paper, we report the detailed protocol of integrating high throughput DNA sequencing into DamID (DamID-seq). The large number of short reads generated from DamID-seq enables detecting and localizing protein-DNA interactions genome-wide with high precision and sensitivity. We have used the DamID-seq assay to study genome-nuclear lamina (NL) interactions in mammalian cells, and have noticed that DamID-seq provides a high resolution and a wide dynamic range in detecting genome-NL interactions. The DamID-seq approach enables probing NL associations within gene structures and allows comparing genome-NL interaction maps with other functional genomic data, such as ChIP-seq and RNA-seq.

We describe herein an assay by coupling DNA adenine methyltransferase identification (DamID) to high throughput sequencing (DamID-seq). This improved method provides a higher resolution and a wider dynamic range, and allows analyzing DamID-seq data in conjunction with other high throughput sequencing data such as ChIP-seq, RNA-seq, etc.

DamID-seq: מיפוי הגנום של אינטראקציות החלבון-DNA על ידי תפוקה גבוהה רצף של קטעי DNA-מפוגל אדנין

The DNA adenine methyltransferase identification (DamID) assay is a powerful method to detect protein-DNA interactions both locally and genome-wide. It is ...

Comparison of Three Different Methods for Determining Cell Proliferation in Breast Cancer Cell Lines

Measuring cell proliferation can be performed by a number of different methods, each with varying levels of sensitivity, reproducibility and compatibility with high-throughput formatting. This protocol describes the use of three different methods for measuring cell proliferation in vitro including conventional hemocytometer counting chamber, a luminescence-based assay that utilizes the change in the metabolic activity of viable cells as a measure of the relative number of cells, and a multi-mode cell imager that measures cell number using a counting algorithm. Each method presents its own advantages and disadvantages for the measurement of cell proliferation, including time, cost and high-throughput compatibility. This protocol demonstrates that each method could accurately measure cell proliferation over time, and was sensitive to detect growth at differing cellular densities. Additionally, measurement of cell proliferation using a cell imager was able to provide further information such as morphology, confluence and allowed for a continual monitoring of cell proliferation over time. In conclusion, each method is capable of measuring cell proliferation, but the chosen method is user-dependent.

This protocol describes the use of three different methods for analyzing cell proliferation in breast cancer cell lines. This includes the use of conventional cell counting, luminescence-based cell viability, and cell counting through the use of a cell imager. Each offers advantages for the reproducible measurement of cell proliferation.

השוואה של שלוש שיטות שונות לקביעת שגשוג תאים בשורות תאי סרטן השד

Measuring cell proliferation can be performed by a number of different methods, each with varying levels of sensitivity, reproducibility and compatibility ...