December 2015 - This Month in JoVE: Flu Surveillance in Swine, DNA Nanorobots, Analyzing Crude Oil, and a Translational Model of Depression

Abstract

Here's a look at what's coming up in the December 2015 issue of JoVE: The Journal of Visualized Experiments. In JoVE Immunology & Infection, we know that the peak of flu season is on its way-and because pigs are important hosts for the influenza A virus, it is critical to monitor virus evolution in swine populations to get a snapshot of current circulating strains. Nasal swabs are a gold-standard technique for taking diagnostic samples from live pigs, but it requires restraining the pigs. Nolting et al. present an alternative sampling method using nasal wipes, which involves rubbing a piece of fabric across the snout of the pig with minimal to no restraint of the animal. The nasal wipe procedure is simple to perform, and virus detection and isolation rates are adequate to make it a viable and low-stress sampling method for flu in pigs. In JoVE Chemistry, DNA nanorobots are hollow hexagonal nanodevices that open in response to specific stimuli to present the cargo sequestered inside. This month, Amir et al. describe a nanorobot fabrication protocol that uses the DNA origami technique. This involves mixing short single-stranded DNA staples with long, circular, single-stranded DNA scaffolds. In a standard thermocycler, the staples anneal to the scaffolds, thus driving the folding of the nanorobot. After the folding reaction is complete, agarose gel electrophoresis (AGE) is used to visualize and estimate the purity of the DNA nanorobots. Finally, nanorobot fabrication is verified by transmission electron microscopy (TEM). This procedure allows for the construction of complex 2D/3D nano-architecture. In JoVE Environment, crude oil is one of the most valuable natural resources because it is the raw material for many fuels and chemical products. Accurate analysis of crude oil, especially the content of highly toxic hydrogen sulfide (H2S), is essential for developing and implementing safety measures in the event of a release or spill. Heshka and Hager present a multidimensional gas chromatography method for analyzing dissolved hydrogen sulfide in crude oil samples. As far as we know, this is the only method that can accurately measure dissolved hydrogen sulfide in heavy crudes, without the use of sub-ambient cooling. In JoVE Behavior, Frisbee et al. present one of the most useful models for studying the pathophysiology of depression in rodents. This protocol uses a variety of mild stressors, and after a period of exposure to unpredictable chronic mild stress, rodents develop behaviors and cardiovascular alterations that are comparable to the symptoms of clinical depression. This approach allows for detailed studies of the pathological mechanisms of chronic stress, and can be used to test new therapies and interventions for chronic stress-induced depression. You've just had a sneak peek of the December 2015 issue of JoVE. Visit the website to see the full-length articles, plus many more, in JoVE: The Journal of Visualized Experiments.