ברצוננו להודות לקרן אמריקה וודאפון, ביל ומלינדה גייטס, וסאו פאולו קרן המחקר (FAPESP) למימון מחקר זה. כמו כן, אנו רוצים להודות לחברי סגל רבים מהמחלקה לאנטומולוגיה באוניברסיטת קליפורניה, ריברסייד, לעצתם על הפרויקט הזה.

<ol>
	<li>Kahn, M. C., Celestin, W., Offenhauser, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recording+of+sounds+produced+by+certain+disease-carrying+mosquitoes.">Recording of sounds produced by certain disease-carrying mosquitoes.</a> Science. 101 (2622), 335-336 (1945).</li><li>Reed, S. C., Williams, C. M., Chadwick, L. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Frequency+of+wing-beat+as+a+character+for+separating+species+races+and+geographic+varieties+of+Drosophila.">Frequency of wing-beat as a character for separating species races and geographic varieties of Drosophila.</a> Genetics. 27 (3), 349 (1942).</li><li>Belton, P., Costello, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Flight+sounds+of+the+females+of+some+mosquitoes+of+Western+Canada.">Flight sounds of the females of some mosquitoes of Western Canada.</a> Entomologia experimentalis et applicata. 26 (1), 105-114 (1979).</li><li>Mankin, R. W., Machan, R., Field Jones, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=testing+of+a+prototype+acoustic+device+for+detection+of+Mediterranean+fruit+flies+flying+into+a+trap.">testing of a prototype acoustic device for detection of Mediterranean fruit flies flying into a trap.</a> Proc. 7th Int Symp Fruit Flies of Economic Importance. , 10-15 (2006).</li><li>Raman, D. R., Gerhardt, R. R., Wilkerson, J. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detecting+insect+flight+sounds+in+the+field+Implications+for+acoustical+counting+of+mosquitoes.">Detecting insect flight sounds in the field Implications for acoustical counting of mosquitoes.</a> Transactions of the ASABE. 50 (4), 1481 .</li><li>Moore, A., Miller, J. R., Tabashnik, B. E., Gage, S. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Automated+identification+of+flying+insects+by+analysis+of+wingbeat+frequencies.">Automated identification of flying insects by analysis of wingbeat frequencies.</a> Journal of economic entomology. 79 (6), 1703-1706 (1986).</li><li>Moore, A., Miller, R. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Automated+identification+of+optically+sensed+aphid+(Homoptera:+Aphidae)+wingbeat+waveforms.">Automated identification of optically sensed aphid (Homoptera: Aphidae) wingbeat waveforms.</a> Annals of the Entomological Society of America. 95 (1), 1-8 (2002).</li><li>Li, Z., Zhou, Z., Shen, Z., Yao, Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Automated+identification+of+mosquito+(diptera:+Culicidae)+wingbeat+waveform+by+artificial+neural+network.">Automated identification of mosquito (diptera: Culicidae) wingbeat waveform by artificial neural network.</a> Artificial Intelligence Applications and Innovations. , 483-489 (2005).</li><li>Moore, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Artificial+neural+network+trained+to+identify+mosquitoes+in+flight.">Artificial neural network trained to identify mosquitoes in flight.</a> Journal of insect behavior. 4 (3), 391-396 (1991).</li><li>Halevy, A., Norvig, P., Pereira, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+unreasonable+effectiveness+of+data.">The unreasonable effectiveness of data.</a> Intelligent Systems, IEEE. 24 (2), 8-12 (2009).</li><li>Banko, M., Brill, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mitigating+the+paucity-of-data+problem+exploring+the+effect+of+training+corpus+size+on+classifier+performance+for+natural+language+processing.">Mitigating the paucity-of-data problem exploring the effect of training corpus size on classifier performance for natural language processing.</a> , 1-5 (2001).</li><li>Shotton, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Real-time+human+pose+recognition+in+parts+from+single+depth+images.">Real-time human pose recognition in parts from single depth images.</a> Communications of the ACM. 56 (1), 116-124 (2013).</li><li>Ilyas, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Classifying+insects+on+the+fly.">Classifying insects on the fly.</a> Ecological Informatics. , (2013).</li><li>Mack, Y. P., Rosenblatt, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multivariate+k-nearest+neighbor+density+estimates.">Multivariate k-nearest neighbor density estimates.</a> Journal of Multivariate Analysis. 9 (1), 1-15 (1979).</li><li>Benedict, M., Robinson, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+first+releases+of+transgenic+mosquitoes+an+argument+for+the+sterile+insect+technique.">The first releases of transgenic mosquitoes an argument for the sterile insect technique.</a> TRENDS in Parasitology. 19 (8), 349-355 (2003).</li><li>. Supporting Materials Available from: <a target="_blank" href="https://sites.google.com/site/insectclassification">https://sites.google.com/site/insectclassification</a></li><li>Chen, Y., Why, A., Batista, G., Mafra-Neto, A., Keogh, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Flying+Insect+Classification+with+Inexpensive+Sensors.">Flying Insect Classification with Inexpensive Sensors.</a> Journal of Insect. 27 (5), 657-677 (2014).</li></ol>

החוקרים מצהירים כי אין להם אינטרסים כלכליים מתחרים.

מסגרת חיישן / הסיווג המתואר כאן מאפשרת סיווג הזול וניתן להרחבה של חרקים מעופפים. דיוקי השגה על ידי המערכת טובים מספיק כדי לאפשר הפיתוח של מוצרים מסחריים ויכולים להיות כלי שימושי במחקר האנטומולוגי. היכולת להשתמש בחיישנים זולים, ל?...

הרעיון של סיווג אוטומטי של חרקים באמצעות הקול הנלווה של הטיסה שלהם שתחילתה בימים הראשונים של מחשבים וציוד זמין מסחרי הקלטת אודיו 1. עם זאת, התקדמות מועטת נעשתה על בעיה זו בעשורים שחלפו. חוסר ההתקדמות במרדף הזה ניתן לייחס לגורמים קשורים כמה. ראשית, חוסר חיישנים יעילים הפך את איסוף הנתונים קשה. רוב המאמצים לאסוף נתונים השתמשו מיקרופוני אקוסטי 2-5. מכשירים כאלה רגישים במיוחד לרוח רעש ורעש הסביבה בסביבה, וכתוצאה מכך הנתונים מאוד דלילים ואיכות נמוכה. שנית, הרכבה בעיות איכות נתונים אלה היא העובדה שחוקרים רבים ניסו ללמוד מודלים סיווג מאוד מסובכים, במיוחד רשתות עצביות 6-8. מנסה ללמוד מודלים סיווג מסובכים, עם עשרות בלבד של דוגמאות,הוא מתכון להתאמת יתר. שלישית, בקשיים של נתוני קבלת יש משמעות דבר כי חוקרים רבים ניסו לבנות מודלים סיווג עם נתונים מאוד מוגבלים, כמה כמו 300 מקרים 9 או פחות. עם זאת, ידוע כי לבניית מודלים סיווג מדויקים, יותר נתונים הוא טובים יותר 10-13. עבודה זו מתייחסת לכל שלושת נושאים. אופטי חיישנים (ולא אקוסטי) ניתן להשתמש כדי להקליט את &quot;קול&quot; של טיסת חרקים ממטרים, עם invariance מלא לרוח רעש וקולות סביבה. חיישנים אלה אפשרו ההקלטה של ​​מיליון מקרי אימון שכותרתו, הרבה יותר נתונים מאשר כל המאמצים הקודמים בשילוב, ובכך לסייע במניעת מאמצי מחקר הקודמים אשר הטריד הולם מעל. שיטה עקרונית מוצגת להלן, המאפשרת שילוב של מידע נוסף למודל הסיווג. מידע נוסף זה יכול להיות כיומיומי וכפי שקל להשגה כמו בזמן של היום, אך עדיין לייצר רווחים משמעותיים ברמת דיוק של המודל. לבסוף, הוא הוכיח כי הכמויות עצומות של נתונים שאספנו תאפשר לנו לנצל את &quot;יעילות בלתי סבירה של נתונים&quot; 10 לייצר מסווגים פשוט, מדויקת וחזקה. לסיכום, סיווג חרקים מעופף עבר מעבר לטענות המפוקפקות שנוצרו במעבדת המחקר וכעת הוא מוכן לפריסה בעולם האמיתי. החיישנים והתוכנה שהוצגו בעבודה זו יספק לחוקרים ברחבי העולם כלים חזקים כדי להאיץ את המחקר שלהם.

<table border="0" cellpadding="0" cellspacing="0" width="1293">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:328px;">Name of Material/ Equipment</td>
			<td style="width:237px;">Company</td>
			<td style="width:257px;">Catalog Number</td>
			<td style="width:471px;">Comments/Description</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:328px;">Audio Recorder: ICD-PX312</td>
			<td style="width:237px;">Sony</td>
			<td style="width:257px;">4-267-065-11(2)</td>
			<td>With a 8 GB microSD extra memory</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:328px;">Insectary</td>
			<td style="width:237px;">Lee&#39;s Aquarium &#38; Pet Products.</td>
			<td style="width:257px;">20088 HerpHaven&#174;, Large Rectangle</td>
			<td style="width:471px;">14 1/2&#34; Long x 8 3/4&#34; Wide x 9 3/4&#34; high. Modified to house insects.&#160;</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:328px;">Laser Line Generator, 650nm (red)</td>
			<td style="width:237px;">Apinex (www.apinex.com)</td>
			<td style="width:257px;">LN60-650</td>
			<td style="width:471px;">5mW. This is a low powered laser, similar to a teachers lasers pointer</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:328px;">Photodiode Array</td>
			<td style="width:237px;">VISHAY SEMICONDUCTOR&#160; TEFD4300&#160; PIN PHOTODIODE, 650NM, 20DEG, T1</td>
			<td style="width:257px;">TEFD4300</td>
			<td style="width:471px;">We made a custom array of 15 of these Photodiodes wired in parallel</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;">Analogue to Digital Convertor Integrated Circuit&#160;</td>
			<td style="width:237px;">Custom made in our lab</td>
			<td style="width:257px;"></td>
			<td style="width:471px;">We made this item ourselves, but an easily available commercial product, Gino PCF8591 AD/DA Converter, provides the same functionality.&#160;</td>
		</tr>
	</tbody>
</table>

flying insect detection and classification with inexpensive sensors

מערכת זולה, לא פולשנית שיכול במדויק לסווג חרקים מעופפים תהיה ההשלכות חשובות למחקר האנטומולוגי, ולאפשר לפיתוח יישומים שימושיים רבים בוקטור והדברה עבור שתי אנטומולוגיה הרפואית וחקלאית. לאור זאת, שישים השנה האחרונה ראתה את מאמצי מחקר רבים שהוקדשו למשימה זו. עד כה, עם זאת, אף אחד ממחקר זה יש לו השפעה ארוכת טווח. בעבודה זו, אנו מראים כי חיישנים אופטיים פסאודו אקוסטי יכולים לייצר נתונים מעולים; כי תכונות נוספות, שניהם פנימיים וחיצוני לחרק טיסת התנהגות, ניתן לנצל כדי לשפר את סיווג חרקים; שגישת סיווג בייס מאפשרת ללמוד ביעילות מודלים סיווג, כי הם מאוד חזקים כדי הולמים מעל, ומסגרת סיווג כללית מאפשרת לשלב מספר שרירותי של תכונות בקלות. אנו מדגימים את הממצאים בניסויים בקנה מידה גדולה שמגמדים את כל העבודות הקודמות COMBIנד, כפי שהיא נמדדת על ידי המספר של חרקים ומספר המינים נחשבים.

שני ניסויים מוצגים כאן. עבור שני הניסויים, הנתונים המשמשים נדגמו באופן אקראי מתוך מאגר הנתונים המכילים למעלה מ 100,000 אובייקטים. הניסוי הראשון מראה את היכולת של מסווג הציעו לסווג במדויק מינים / מינים שונים של חרקים. כדיוק הסיווג תלו...

Watch this Scientific Journal Video about Flying Insect Detection and Classification with Inexpensive Sensors at JoVE.com

Flying Insect Detection and Classification with Inexpensive Sensors

הצענו מערכת שמשתמשת בחיישנים זולים, לא פולשנית פסאודו אקוסטי אופטיים באופן אוטומטי ומדויק לאתר, לספור, ולסווג את חרקים מעופפים המבוססים על קול הטיסה שלהם.

טיסה חרקים באיתור ובסיווג עם חיישנים זולים

An inexpensive, noninvasive system that could accurately classify flying insects would have important implications for entomological research, and allow ...

flying-insect-detection-and-classification-with-inexpensive-sensors

Universidad de Cartagena UDEC

Research

JoVE Journal

Bioengineering

25.0K Views.  University of California, Riverside.  הצענו מערכת שמשתמשת בחיישנים זולים, לא פולשנית פסאודו אקוסטי אופטיים באופן אוטומטי ומדויק לאתר, לספור, ולסווג את חרקים מעופפים המבוססים על קול הטיסה שלהם. 

Video: Flying Insect Detection and Classification with Inexpensive Sensors

Fluorescence detection methods for microfluidic droplet platforms

The development of microfluidic platforms for performing chemistry and biology has in large part been driven by a range of potential benefits that accompany system miniaturisation. Advantages include the ability to efficiently process nano- to femoto- liter volumes of sample, facile integration of functional components, an intrinsic predisposition towards large-scale multiplexing, enhanced analytical throughput, improved control and reduced instrumental footprints.1
In recent years much interest has focussed on the development of droplet-based (or segmented flow) microfluidic systems and their potential as platforms in high-throughput experimentation.2-4 Here water-in-oil emulsions are made to spontaneously form in microfluidic channels as a result of capillary instabilities between the two immiscible phases. Importantly, microdroplets of precisely defined volumes and compositions can be generated at frequencies of several kHz. Furthermore, by encapsulating reagents of interest within isolated compartments separated by a continuous immiscible phase, both sample cross-talk and dispersion (diffusion- and Taylor-based) can be eliminated, which leads to minimal cross-contamination and the ability to time analytical processes with great accuracy. Additionally, since there is no contact between the contents of the droplets and the channel walls (which are wetted by the continuous phase) absorption and loss of reagents on the channel walls is prevented.
Once droplets of this kind have been generated and processed, it is necessary to extract the required analytical information. In this respect the detection method of choice should be rapid, provide high-sensitivity and low limits of detection, be applicable to a range of molecular species, be non-destructive and be able to be integrated with microfluidic devices in a facile manner. To address this need we have developed a suite of experimental tools and protocols that enable the extraction of large amounts of photophysical information from small-volume environments, and are applicable to the analysis of a wide range of physical, chemical and biological parameters. Herein two examples of these methods are presented and applied to the detection of single cells and the mapping of mixing processes inside picoliter-volume droplets. We report the entire experimental process including microfluidic chip fabrication, the optical setup and the process of droplet generation and detection.

Droplet-based microfluidic platforms are promising candidates for high throughput experimentation since they are able to generate picoliter, self-compartmentalized vessels inexpensively at kHz rates. Through integration with fast, sensitive and high resolution fluorescence spectroscopic methods, the large amounts of information generated within these systems can be efficiently extracted, harnessed and utilized.

שיטות גילוי הקרינה לפלטפורמות אגל microfluidic

The development of microfluidic platforms for performing chemistry and biology has in large part been driven by a range of potential benefits that ...

Detection and Isolation of Circulating Melanoma Cells using Photoacoustic Flowmetry

Circulating tumor cells (CTCs) are those cells that have separated from a macroscopic tumor and spread through the blood and lymph systems to seed secondary tumors1,2,3. CTCs are indicators of metastatic disease and their detection in blood samples may be used to diagnose cancer and monitor a patient&prime;s response to therapy. Since CTCs are rare, comprising about one tumor cell among billions of normal blood cells in advanced cancer patients, their detection and enumeration is a difficult task. We exploit the presence of pigment in most melanoma cells to generate photoacoustic, or laser induced ultrasonic waves in a custom flow cytometer for detection of circulating melanoma cells (CMCs)4,5. This process entails separating a whole blood sample using centrifugation and obtaining the white blood cell layer. If present in whole blood, CMCs will separate with the white blood cells due to similar density. These cells are resuspended in phosphate buffered saline (PBS) and introduced into the flowmeter. Rather than a continuous flow of the blood cell suspension, we induced two phase flow in order to capture these cells for further study. In two phase flow, two immiscible liquids in a microfluidic system meet at a junction and form alternating slugs of liquid6,7. PBS suspended white blood cells and air form microliter slugs that are sequentially irradiated with laser light. The addition of a surfactant to the liquid phase allows uniform slug formation and the user can create different sized slugs by altering the flow rates of the two phases. Slugs of air and slugs of PBS with white blood cells contain no light absorbers and hence, do not produce photoacoustic waves. However, slugs of white blood cells that contain even single CMCs absorb laser light and produce high frequency acoustic waves. These slugs that generate photoacoustic waves are sequestered and collected for cytochemical staining for verification of CMCs.

We have developed a flow cytometer using laser induced ultrasound to detect circulating melanoma cells as an early indicator of metastatic disease.

איתור בידוד של תאים מלנומה במחזור באמצעות Flowmetry photoacoustic

Circulating tumor cells (CTCs) are those cells that have separated from a macroscopic tumor and spread through the blood and lymph systems to seed ...

Bacterial Detection &amp; Identification Using Electrochemical Sensors

Electrochemical sensors are widely used for rapid and accurate measurement of blood glucose and can be adapted for detection of a wide variety of analytes. Electrochemical sensors operate by transducing a biological recognition event into a useful electrical signal. Signal transduction occurs by coupling the activity of a redox enzyme to an amperometric electrode. Sensor specificity is either an inherent characteristic of the enzyme, glucose oxidase in the case of a glucose sensor, or a product of linkage between the enzyme and an antibody or probe.
Here, we describe an electrochemical sensor assay method to directly detect and identify bacteria. In every case, the probes described here are DNA oligonucleotides. This method is based on sandwich hybridization of capture and detector probes with target ribosomal RNA (rRNA). The capture probe is anchored to the sensor surface, while the detector probe is linked to horseradish peroxidase (HRP). When a substrate such as 3,3',5,5'-tetramethylbenzidine (TMB) is added to an electrode with capture-target-detector complexes bound to its surface, the substrate is oxidized by HRP and reduced by the working electrode. This redox cycle results in shuttling of electrons by the substrate from the electrode to HRP, producing current flow in the electrode.

Bacterial Detection & Identification Using Electrochemical Sensors

We describe an electrochemical sensor assay method for rapid bacterial detection and identification. The assay involves a sensor array functionalized with DNA oligonucleotide capture probes for ribosomal RNA (rRNA) species-specific sequences. Sandwich hybridization of target rRNA with the capture probe and a horseradish peroxidase-linked DNA oligonucleotide detector probe produces a measurable amperometric current.

גילוי חיידקים וזיהוי באמצעות חיישנים אלקטרוכימיים

Electrochemical  sensors are widely used for rapid and accurate measurement of blood glucose and  can be adapted for detection of a wide variety of ...

Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria

A structurally transformed lytic bacteriophage having a broad host range of Staphylococcus aureus strains and a penicillin-binding protein (PBP 2a) antibody conjugated latex beads have been utilized to create a biosensor designed for discrimination of methicillin resistant (MRSA) and sensitive (MSSA) S. aureus species 1,2. The lytic phages have been converted into phage spheroids by contact with water-chloroform interface. Phage spheroid monolayers have been moved onto a biosensor surface by Langmuir-Blodgett (LB) technique 3. The created biosensors have been examined by a quartz crystal microbalance with dissipation tracking (QCM-D) to evaluate bacteria-phage interactions. Bacteria-spheroid interactions led to reduced resonance frequency and a rise in dissipation energy for both MRSA and MSSA strains. After the bacterial binding, these sensors have been further exposed to the penicillin-binding protein antibody latex beads. Sensors analyzed with MRSA responded to PBP 2a antibody beads; although sensors inspected with MSSA gave no response. This experimental distinction determines an unambiguous discrimination between methicillin resistant and sensitive S. aureus strains. Equally bound and unbound bacteriophages suppress bacterial growth on surfaces and in water suspensions. Once lytic phages are changed into spheroids, they retain their strong lytic activity and show high bacterial capture capability. The phage and phage spheroids can be utilized for testing and sterilization of antibiotic resistant microorganisms. Other applications may include use in bacteriophage therapy and antimicrobial surfaces.

Lytic phage biosensors and antibody beads are able to discriminate between methicillin resistant (MRSA) and sensitive staphylococcus bacteria. The phages were immobilized by a Langmuir-Blodgett method onto a surface of a quartz crystal microbalance sensor and worked as broad range staphylococcus probes. Antibody beads recognize MRSA.

Biosensor לאיתור של חיידקי סטפילוקוקוס עמידים לאנטיביוטיקה

A structurally transformed lytic bacteriophage having a broad host range of Staphylococcus aureus strains and a penicillin-binding protein (PBP 2a) ...

Glutamine Flux Imaging Using Genetically Encoded Sensors

Genetically encoded sensors allow real-time monitoring of biological molecules at a subcellular resolution. A tremendous variety of such sensors for biological molecules became available in the past 15 years, some of which became indispensable tools that are used routinely in many laboratories.
One of the exciting applications of genetically encoded sensors is the use of these sensors in investigating cellular transport processes. Properties of transporters such as kinetics and substrate specificities can be investigated at a cellular level, providing possibilities for cell-type specific analyses of transport activities. In this article, we will demonstrate how transporter dynamics can be observed using genetically encoded glutamine sensor as an example. Experimental design, technical details of the experimental settings, and considerations for post-experimental analyses will be discussed.

This article will demonstrate how to monitor glutamine dynamics in live cells using FRET. Genetically encoded sensors allow real-time monitoring of biological molecules at a subcellular resolution. Experimental design, technical details of the experimental settings, and considerations for post-experimental analyses will be discussed for genetically encoded glutamine sensors.

גלוטמין שטף הדמיה באמצעות חיישני מקודדים גנטיים

Genetically encoded sensors allow real-time monitoring of biological molecules at a subcellular resolution. A tremendous variety of such sensors for ...

A Microfluidic-based Electrochemical Biochip for Label-free DNA Hybridization Analysis

Miniaturization of analytical benchtop procedures into the micro-scale provides significant advantages in regards to reaction time, cost, and integration of pre-processing steps. Utilizing these devices towards the analysis of DNA hybridization events is important because it offers a technology for real time assessment of biomarkers at the point-of-care for various diseases. However, when the device footprint decreases the dominance of various physical phenomena increases. These phenomena influence the fabrication precision and operation reliability of the device. Therefore, there is a great need to accurately fabricate and operate these devices in a reproducible manner in order to improve the overall performance. Here, we describe the protocols and the methods used for the fabrication and the operation of a microfluidic-based electrochemical biochip for accurate analysis of DNA hybridization events. The biochip is composed of two parts: a microfluidic chip with three parallel micro-channels made of polydimethylsiloxane (PDMS), and a 3 x 3 arrayed electrochemical micro-chip. The DNA hybridization events are detected using electrochemical impedance spectroscopy (EIS) analysis. The EIS analysis enables monitoring variations of the properties of the electrochemical system that are dominant at these length scales. With the ability to monitor changes of both charge transfer and diffusional resistance with the biosensor, we demonstrate the selectivity to complementary ssDNA targets, a calculated detection limit of 3.8 nM, and a 13% cross-reactivity with other non-complementary ssDNA following 20 min&#160;of incubation. This methodology can improve the performance of miniaturized devices by elucidating on the behavior of diffusion at the micro-scale regime and by enabling the study of DNA hybridization events.

We present a microfluidic-based electrochemical biochip for DNA hybridization detection. Following ssDNA probe functionalization, the specificity, sensitivity, and detection limit are studied with complementary and non-complementary ssDNA targets. Results illustrate the influence of the DNA hybridization events on the electrochemical system, with a detection limit of 3.8 nM.

Biochip אלקטרוכימי מבוסס Microfluidic לניתוח הכלאה DNA ללא תווית

Miniaturization of analytical benchtop procedures into the micro-scale provides significant advantages in regards to reaction time, cost, and integration ...

Detection of Exosomal Biomarker by Electric Field-induced Release and Measurement (EFIRM)

Exosomes are microvesicular structures that play a mediating role in intercellular communication. It is of interest to study the internal cargo of exosomes to determine if they carry disease discriminatory biomarkers. For performing exosomal analysis, it is necessary to develop a method for extracting and analyzing exosomes from target biofluids without damaging the internal content.
Electric field-induced release and measurement (EFIRM) is a method for specifically extracting exosomes from biofluids, unloading their cargo, and testing their internal RNA/protein content. Using an anti-human CD63 specific antibody magnetic microparticle, exosomes are first precipitated from biofluids. Following extraction, low-voltage electric cyclic square waves (CSW) are applied to disrupt the vesicular membrane and cause cargo unloading. The content of the exosome is hybridized to DNA primers or antibodies immobilized on an electrode surface for quantification of molecular content.
The EFIRM method is advantageous for extraction of exosomes and unloading cargo for analysis without lysis buffer. This method is capable of performing specific detection of both RNA and protein biomarker targets in the exosome. EFIRM extracts exosomes specifically based on their surface markers as opposed to size-based techniques.
Transmission electron microscopy (TEM) and assay demonstrate the functionality of the method for exosome capture and analysis. The EFIRM method was applied to exosomal analysis of 9 mice injected with human lung cancer H640 cells (a cell line transfected to express the exosome marker human CD63-GFP) in order to test their exosome profile against 11 mice receiving saline controls. Elevated levels of exosomal biomarkers (reference gene GAPDH and protein surface marker human CD63-GFP) were found for the H640 injected mice in both serum and saliva samples. Furthermore, saliva and serum samples were demonstrated to have linearity (R = 0.79). These results are suggestive for the viability of salivary exosome biomarkers for detection of distal diseases.

Detection of Exosomal Biomarker by Electric Field-induced Release and Measurement EFIRM

Exosomes are microvesicular structures found within biofluids that potentially carry important disease discriminatory biomarkers. Here, a novel method is used to specifically extract exosomes and rapidly test the exosomal cargo for both RNA/protein targets following the disruption of exosomes using non-uniform electric cyclic square waves.

איתור של Exosomal ביומרקר על ידי שחרור מושרה שדה חשמלי ומדידה (EFIRM)

Exosomes are microvesicular structures that play a mediating role in intercellular communication. It is of interest to study the internal cargo of ...

Label-free Single Molecule Detection Using Microtoroid Optical Resonators

Detecting small concentrations of molecules down to the single molecule limit has impact on areas such as early detection of disease, and fundamental studies on the behavior of molecules. Single molecule detection techniques commonly utilize labels such as fluorescent tags or quantum dots, however, labels are not always available, increase cost and complexity, and can perturb the events being studied. Optical resonators have emerged as a promising means to detect single molecules without the use of labels. Currently the smallest particle detected by a non-plasmonically-enhanced bare optical resonator system in solution is a 25 nm polystyrene sphere1. We have developed a technique known as Frequency Locking Optical Whispering Evanescent Resonator (FLOWER) that can surpass this limit and achieve label-free single molecule detection in aqueous solution2. As signal strength scales with particle volume, our work represents a &#62; 100x improvement in the signal to noise ratio (SNR) over the current state of the art. Here the procedures behind FLOWER are presented in an effort to increase its usage in the field.

We have developed a label-free biosensing system based on optical resonator technology known as Frequency Locking Optical Whispering Evanescent Resonator (FLOWER) that is capable of detecting single molecules in solution. Here the procedures behind this work are described and presented.

ללא תווית מולקולה בודדת איתור באמצעות תהודה אופטית Microtoroid

Detecting small concentrations of molecules down to the single molecule limit has impact on areas such as early detection of disease, and fundamental ...

Sensitive Detection of Proteopathic Seeding Activity with FRET Flow Cytometry

Increasing evidence supports transcellular propagation of toxic protein aggregates, or proteopathic seeds, as a mechanism for the initiation and progression of pathology in several neurodegenerative diseases, including Alzheimer's disease and the related tauopathies. The potentially critical role of tau seeds in disease progression strongly supports the need for a sensitive assay that readily detects seeding activity in biological samples. 
By combining the specificity of fluorescence resonance energy transfer (FRET), the sensitivity of flow cytometry, and the stability of a monoclonal cell line, an ultra-sensitive seeding assay has been engineered and is compatible with seed detection from recombinant or biological samples, including human and mouse brain homogenates. The assay employs monoclonal HEK 293T cells that stably express the aggregation-prone repeat domain (RD) of tau harboring the disease-associated P301S mutation fused to either CFP or YFP, which produce a FRET signal upon protein aggregation. The uptake of proteopathic tau seeds (but not other proteins) into the biosensor cells stimulates aggregation of RD-CFP and RD-YFP, and flow cytometry sensitively and quantitatively monitors this aggregation-induced FRET. The assay detects femtomolar concentrations (monomer equivalent) of recombinant tau seeds, has a dynamic range spanning three orders of magnitude, and is compatible with brain homogenates from tauopathy transgenic mice and human tauopathy subjects. With slight modifications, the assay can also detect seeding activity of other proteopathic seeds, such as &#945;-synuclein, and is also compatible with primary neuronal cultures. The ease, sensitivity, and broad applicability of FRET flow cytometry makes it useful to study a wide range of protein aggregation disorders.

Cell-to-cell transfer of protein aggregates, or proteopathic seeds, may underlie the progression of pathology in neurodegenerative diseases. Here, a novel FRET flow cytometry assay is described that enables specific and sensitive detection of seeding activity from recombinant or biological samples.

איתור רגיש של פעילות זריעת Proteopathic עם סריג cytometry הזרימה

Increasing evidence supports transcellular propagation of toxic protein aggregates, or proteopathic seeds, as a mechanism for the initiation and ...

Fast Enzymatic Processing of Proteins for MS Detection with a Flow-through Microreactor

The vast majority of mass spectrometry (MS)-based protein analysis methods involve an enzymatic digestion step prior to detection, typically with trypsin. This step is necessary for the generation of small molecular weight peptides, generally with MW &#60; 3,000-4,000 Da, that fall within the effective scan range of mass spectrometry instrumentation. Conventional protocols involve O/N enzymatic digestion at 37 &#186;C. Recent advances have led to the development of a variety of strategies, typically involving the use of a microreactor with immobilized enzymes or of a range of complementary physical processes that reduce the time necessary for proteolytic digestion to a few minutes (e.g., microwave or high-pressure). In this work, we describe a simple and cost-effective approach that can be implemented in any laboratory for achieving fast enzymatic digestion of a protein. The protein (or protein mixture) is adsorbed on C18-bonded reversed-phase high performance liquid chromatography (HPLC) silica particles preloaded in a capillary column, and trypsin in aqueous buffer is infused over the particles for a short period of time. To enable on-line MS detection, the tryptic peptides are eluted with a solvent system with increased organic content directly in the MS ion source. This approach avoids the use of high-priced immobilized enzyme particles and does not necessitate any aid for completing the process. Protein digestion and complete sample analysis can be accomplished in less than ~3 min and ~30 min, respectively.

A quick protocol for proteolytic digestion with an in-house built flow-through tryptic microreactor coupled to an electrospray ionization (ESI) mass spectrometer is presented. The fabrication of the microreactor, the experimental setup and the data acquisition process are described.

עיבוד אנזימתי תענית חלבונים עבור איתור MS עם microreactor זרימה דרך

The vast majority of mass spectrometry (MS)-based protein analysis methods involve an enzymatic digestion step prior to detection, typically with trypsin. ...