<h2 class="jove_title"><a href="https://www.jove.com/video/52619">Dried Blood Spots &#8212; Preparing and Processing for Use in Immunoassays and in Molecular Techniques</a></h2>Nico Gr&#252;ner, Oumaima Stambouli, R. Stefan RossInstitute of Virology, National Reference Centre for Hepatitis C, Essen University Hospital, University of Duisburg-EssenThe preparing and processing of dried blood spots (DBS) for their final analysis are still poorly standardized for most diagnostic applications. To overcome this shortcoming, a comprehensive step-by-step protocol is suggested and subsequently evaluated with regard to its effectiveness for detecting markers of viral infections.<h2 class="jove_title"><a href="https://www.jove.com/video/52337">A Technical Perspective in Modern Tree-ring Research &#8212; How to Overcome Dendroecological and Wood Anatomical Challenges</a></h2>Holger G&#228;rtner, Paolo Cherubini, Patrick Fonti, Georg von Arx, Lo&#239;c Schneider, Daniel Nievergelt, Anne Verstege, Alexander Bast, Fritz H. Schweingruber, Ulf B&#252;ntgenLandscape Dynamics &#47; Dendroecology, Swiss Federal Research Institute WSLHere we present a protocol outlining how to sample wooden specimens for the overall assessment of their growth structures. Macro- and microscopic preparation and visualization techniques necessary to generate well-replicated and highly resolved wood anatomical and dendroecological dataset, are described are described.<h2 class="jove_title"><a href="https://www.jove.com/video/52612">Enhanced Genetic Analysis of Single Human Bioparticles Recovered by Simplified Micromanipulation from Forensic &#8216;Touch DNA&#8217; Evidence</a></h2>Katherine Farash1,2, Erin K. Hanson3, Jack Ballantyne1,2,31Forensic Science Graduate Program, Biochemistry Track, University of Central Florida, 2Department of Chemistry, University of Central Florida, 3National Center for Forensic Science, University of Central FloridaHere we describe an optimized and efficient removal strategy for the collection of bio-particles present in &#8216;touch DNA&#8217; samples, together with an enhanced amplification protocol involving a one-step 5 &#181;l micro-volume lysis/STR amplification, to permit the recovery of short tandem repeat (STR) profiles of the bio-particle donor(s).<h2 class="jove_title"><a href="https://www.jove.com/video/52616">Sealable Femtoliter Chamber Arrays for Cell-free Biology</a></h2>Sarah Elizabeth Norred1,2, Patrick M. Caveney1,2, Scott T. Retterer1,2, Jonathan B. Boreyko1,2, Jason D. Fowlkes2,3, Charles Patrick Collier2, Michael L. Simpson1,2,31Bredesen Center, University of Tennessee, Knoxville, 2Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, 3Department of Materials Science and Engineering, University of Tennessee, KnoxvilleA microfabricated device with sealable femtoliter-volume reaction chambers is described. This report includes a protocol for sealing cell-free protein synthesis reactants inside these chambers for the purpose of understanding the role of crowding and confinement in gene expression.

march 2015: this month in jove - solving crime with science, applying technology to understand trees, and studying protein synthesis on a chip

Here's a look at what's coming up in the <a href="http://www.jove.com/archive/97">March 2015 issue</a> of <a href="http://www.jove.com/">JoVE: The Journal of Visualized Experiments</a>.
In <a href="http://www.jove.com/enviro">JoVE Environment</a>, we really love trees-especially for the data stored in tree rings, which are not only valued by historians, geologists, and archeologists, but also environmental scientists who study how forest ecosystems respond to environmental changes. <a href="http://www.jove.com/video/52337/">G&#228;rtner et al.</a> expand on traditional tree ring research with new protocols for sampling, preparing, and analyzing wooden specimens. They also present a way to resolve digital images for time-series analyses. These techniques will help scientists understand the effects of specific environmental factors on trees and other woody plants.
In <a href="http://www.jove.com/biology">JoVE Biology</a>, we have two protocols that can be used in forensic investigations. 
When individuals touch objects or other individuals, they can transfer cellular material that contains traces of DNA. But recovering this DNA from a forensic sample is like finding a needle in a haystack. Therefore, <a href="http://www.jove.com/video/52612/">Gr&#252;ner et al.</a> use a targeted approach, zeroing in on potential biological material under a microscope, and amplifying DNA microsatellite markers called short tandem repeats (STRs). Using bioparticles collected from various objects, they successfully obtain useful genetic profiles from "touch DNA" evidence.
Also in <a href="http://www.jove.com/biology">JoVE Biology</a>, scientists have been collecting blood on filter paper for diagnostic and forensic analyses for over a century. But after all this time, protocols for preparing and processing dried blood spots remain poorly standardized. So <a href="http://www.jove.com/video/52619/">Farash et al.</a> present a comprehensive, step-by-step protocol for collecting blood, preparing blood spots; drying and storing the filter papers, and eluting the blood for analysis. They demonstrate the effectiveness of this protocol by detecting markers of various viral infections on an automated analytical platform, and in a pilot study for detecting viral infections in active drug users.
In <a href="http://www.jove.com/bioengineering">JoVE Bioengineering</a>, all the extrinsic "noise" in living cell systems can complicate the study of specific cellular processes. So scientists use cell-free systems to study the dynamics of biological reactions, such as the intrinsic noise of protein synthesis. <a href="http://www.jove.com/video/52616/">Norred et al.</a> present a microfabricated device that can confine cell-free protein synthesis to femtoliter-scale reaction volumes. They demonstrate how to use this device to measure the noise of protein expression in a confined cell-free environment.
You've just had a sneak peek of the <a href="http://www.jove.com/archive/97">March 2015 issue</a> of JoVE. Visit the website to see the full-length articles, plus many more, in <a href="http://www.jove.com/">JoVE: The Journal of Visualized Experiments</a>.

Watch this Scientific Journal Video about March 2015: This Month in JoVE - Solving Crime with Science, Applying Technology to Understand Trees, and Studying Protein Synthesis on a Chip at JoVE.com

March 2015: This Month in JoVE - Solving Crime with Science, Applying Technology to Understand Trees, and Studying Protein Synthesis on a Chip

Here's a look at what's coming up in the March 2015 issue of JoVE: The Journal of Visualized Experiments.
In JoVE Environment, we really love ...

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1.5K vues.  Massachusetts Eye and Ear. March 2015: This Month in JoVE - Solving Crime with Science, Applying Technology to Understand Trees, and Studying Protein Synthesis on a Chip

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August 2012: This Month in JoVE

Traditional microscopy requires lens objectives to magnify specimens, and can involve numerous optical components like additional objectives, filters, and mirrors to refract and direct light to optical sensors. The August 2012 issue of JoVE (Journal of Visualized Experiments) is marked by the third publication from the Ozcan Lab (University of California, Los Angeles) on their lens free lens-free "on-chip" microscopy platform, which they have pioneered.
Back in 2009, the Ozcan lab published their first article, which demonstrated the use of a lens-free imaging platform that could image cells within whole blood. This imaging technique involves placing a sample directly on an optoelectric sensor array, like the CCD or CMOS chips found in the standard camcorder. Then, LED illumination from above the sample casts shadows on the chip, which are recorded as digital holograms that can be subjected to image processing. Not only does this lensless imaging system allow for an extremely large field of view (FOV of 0.6-8 cm2), the lack of bulky optical components makes it excellent for microfluidic applications. The Ozcan group demonstrates this in their follow-up 2011 JoVE article, in which fluorescently labeled white blood cells are imaged within a microfluidic chip.
This August in JoVE, the Ozcan group demonstrates further advancements to their lens-free microscopy platform by applying it to tomographic imaging of the nematode, C. elegans. By changing the angle of illumination, using a motorized rotation stage, the Ozcan group shows how multiple holographic slices may be generated for a sample-which, following processing, can be combined into tomograms. The Ozcan group confirms that their 3D reconstruction of the worm is successful by citing that the pharyngeal tube, a 5-micron-thick structure, is only visible in a single slice and in a 3D reconstructed cross section.
The compact and inexpensive nature of the lens-free imaging systems - designed and assembled by the Ozcan group - make them well suited for point-of-care diagnostic applications, or even cell phone based microscopy that can be performed in the field.
At the Ernest Gallo Clinic and Research Center at University of California, San Francisco JoVE learns how to visualize morphological changes in single cells using three-dimensional fluorescence microscopy and computer analysis. In this procedure, cells are given agonist, antagonist plus agonist, or no treatment, and prepared for immunofluorescence microscopy. Three-dimensional images are acquired with the help of a two-photon laser system, and the fluorescence data are processed on the computer using Imaris and Matlab.
To demonstrate the power of this technique, our authors quantify single-cell phenotypic changes in transfected HEK293 cells. Three-dimensional morphometric analysis shows dramatic changes in cells treated with agonist. These changes are not always apparent when using conventional 2D analysis. This technique allows morphological changes in single cells to be quantified and characterized in response to pharmacologic stimuli, offering a powerful new assessment tool to the arsenal of drug discovery research.
This month, in JoVE Applied Physics, we travel to South Carolina to visit the School of Materials Science and Engineering at Clemson University. Here, researchers show us how to construct lithium batteries for laboratory research.
The basic components of a lithium coin cell are the working electrode, the lithium electrolyte, and a lithium foil counter electrode. The different components of the coin cell are carefully assembled and sealed with a crimping machine. The finished coin cell can then be characterized in a battery tester. Using their homemade coin cells, our researchers can experiment with using different materials to make the cathodes of lithium coin cells.
This month in JoVE Immunology and Infection, we head to Basel, Switzerland to witness two techniques for diagnosing helminth infections. We also see how investigators perform the shuttle run test in children, in order to assess the effects of these infections on physical fitness.
Helminths are parasitic worms that can live inside humans and animals. Many species infect the intestinal tract, and may be transmitted through soil. Our authors demonstrate the Kato-Katz technique, which is used for diagnosing several common soil-transmitted helminths. They also demonstrate the Baermann technique, which uses light to stimulate the migration of certain types of phototactic helminths out of sample preparations. The various types of helminth species can subsequently be determined based on morphology.
Our authors then demonstrate how to set up and perform a 20-meter shuttle run test for children, and to measure the impact of helminth infections on physical fitness. This method can help determine the true burden of soil-transmitted helminth infections on overall health.
This brief summary highlights but a few notable video-articles that will be released in August. We'll also feature articles that demonstrate how to express genes in the midbrain of the chick embryo, study neutrophil transmigration in parallel flow chambers lined with endothelial cells, and precisely measure proteolytic degradation of the extracellular matrix.

Traditional microscopy requires lens objectives to magnify specimens, and can involve numerous optical components like additional objectives, filters, and mirrors to refract and direct light to optical sensors. The August 2012 issue of JoVE (Journal of Visualized Experiments) is marked by the third publication from the Ozcan Lab (University of California, Los Angeles) on their lens-free "on-chip" microscopy platform, which they have pioneered.

Août 2012: Ce mois-ci dans JoVE

Traditional microscopy requires lens objectives to magnify specimens, and can involve numerous optical components like additional objectives, filters, and ...

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2012: A Year In Review

Here's a look at some of the milestones and highlights of the year 2012 in Journal of Visualized Experiments (JoVE).
At the start of 2012, JoVE reached a major milestone by publishing our 1500th article. In this publication, in JoVE Bioengineering, Yu et al. described a method for analyzing the free radical composition of cigarette smoke. This method simulated cigarette puffing with a single-port smoking device, and combined it with electron spin resonance (ESR) spectroscopy to measure the degree to which antioxidant compounds can scavenge free radicals in cigarette smoke. A possible outcome of this research is the creation of less harmful cigarettes.
JoVE Bioengineering also contained the most-viewed article of 2012. Owczarczak et al. described a method for hacking a standard inkjet printer, loading ink cartridges with a cell-suspension "bioink," and printing lines of live cells onto glass slides. The thermal inkjet printing process creates temporary pores in the cell membrane, visualized by the incorporation of fluorescently labeled actin monomers. This concept, called "bioprinting," has many potential applications in cell and tissue engineering.
Also in 2012, JoVE Bioengineering featured a protocol by Hsia et al. for isolating and purifying spider silk protein, spinning it into fibers, and assessing the fiber strength. This protocol for laboratory-scale production of spider silk, which is stronger than tensile steel, can potentially be extended to large-scale manufacturing.
In JoVE Clinical and Translational Medicine, we featured a number of articles related to stroke, one of which. In one article, M&ouml;bius-Winkler et al. demonstrated placement of the WATCHMAN left atrial appendage occlusion device from Boston Scientific. This device is designed to prevent strokes by trapping clots within the left atrial appendage of the heart before they exit. Our authors demonstrated how to insert the guide wire through the femoral artery into the heart, advance the device into the left atrium, and deploy the device in the left atrial appendage.
Another article focused on stroke, Hamel et al. described the use of a driving simulator to study how patients compensate for visual field defects following stroke. By analyzing the compensatory gaze behavior of patients as they navigated through virtual driving courses with varying degrees of complexity, our authors see great potential for the use of driving simulators in stroke rehabilitation.
In JoVE Immunology and Infection, we published an article by Keyel et al. describing the real-time kinetics of immune cell responses to bacterial toxins using live cell microscopy. Combined with high-speed 3D confocal microscopy, this technique can also visualize the cellular repair response.
Also in JoVE Immunology and Infection, we featured an article by Yap et al. describing methods for diagnosing helminth infections in children. Helminths are parasitic worms that can infect the intestinal tract of humans and animals, and may be distinguished based on their morphology. The same article demonstrated how to measure the impact of helminth infections on physical fitness in children, which is a measure of overall health.
In JoVE Neuroscience, we featured a method by Hoffmann et al., who used tiny headphones to alter the auditory feedback in songbirds, and analyzed the computational and neurophysiological basis of vocal learning in birds when they adjust their singing in response to altered acoustic signals.
Also in JoVE Neuroscience, we moved from birds to bees with a method that assesses associative and non-associative tactile learning in honeybees. This method, by Mujagi&#263; et al., allowed bees to scan different metal surfaces with their antennae, then conditioned them to expect sugar water when their antennae touched particular surfaces, and analyzed the corresponding changes in antennal movement.
In 2012, we launched a brand-new section: JoVE Applied Physics, which features articles on subjects ranging from plasma physics to material science. The Applied Physics section also contained JoVE's 2000th video article, filmed in a synchrotron radiation facility, where Borisenko et al. showed how to determine the electronic structure of complex materials using angle-resolved photoemission spectroscopy.
In the JoVE General section, we published an article by Artioli et al. demonstrating the use of a portable gas analyzer to measure oxygen consumption during complex exercise - such as judo. By analyzing oxygen consumption and collecting blood for measuring plasma lactate concentration, this method can determine the relative contributions of different energy systems to specific aspects of complex exercise.
Finally, JoVE followed Dolhi et al. to a permanently ice-covered saline lake in Antarctica. There, scientists drilled through the ice to study single-celled microorganisms called protists that live in the harsh conditions of Antarctica.
This Year in Review was just a brief glimpse of a few of over 600 video articles that JoVE offered in 2012. Browse the JoVE archives to see thousands of other videos, and stay tuned for what's coming up this year in JoVE: The Journal of Visualized Experiments.

Here's a look at some of the milestones and highlights of the year 2012 in Journal of Visualized Experiments (JoVE).

2012: Une année en revue

 
 
Here's a look at some of the milestones and highlights of the year 2012 in Journal of Visualized Experiments (JoVE).
At the start of 2012, JoVE ...