February 2013: This Month in JoVE

Summary

Here's a look at what's coming up in the February 2013 Issue of Journal of Visualized Experiments (JoVE).

Protocol

LabVIEW-operated Novel Nanoliter Osmometer for Ice Binding Protein Investigations

Ido Braslavsky^{1, 2}, Ran Drori^1
1Institute of Biochemistry, Food Science, and Nutrition, The Robert H. Smith Faculty of Agriculture, Food, and Environment, The Hebrew University of Jerusalem, ²Department of Physics and Astronomy, Ohio University

Ice binding proteins (IBPs), also known as antifreeze proteins, inhibit ice growth and are a promising additive for use in the cryopreservation of tissues. The main tool used to investigate IBPs is the nanoliter osmometer. We developed a home-designed cooling stage mounted on an optical microscope and controlled using a custom-built LabVIEW routine. The nanoliter osmometer described here manipulated the sample temperature in an ultra-sensitive manner.

Origami Inspired Self-assembly of Patterned and Reconfigurable Particles

Shivendra Pandey¹, Evin Gultepe¹, David H. Gracias^{1, 2
1}Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, ²Department of Chemistry, The Johns Hopkins University

We describe experimental details of the synthesis of patterned and reconfigurable particles from two dimensional (2D) precursors. This methodology can be used to create particles in a variety of shapes including polyhedra and grasping devices at length scales ranging from the micro to centimeter scale.

Rapid Colorimetric Assays To Qualitatively Distinguish RNA And DNA In Biomolecular Samples

Jennifer Patterson, Cameron Mura
Department of Chemistry, University of Virginia

A suite of colorimetric assays is described for rapidly distinguishing protein, RNA, DNA, and re-ducing sugars in potentially heterogeneous biomolecular samples.

Preparation and Use of Samarium Diiodide (SmI₂) in Organic Synthesis: The Mechanistic Role of HMPA and Ni(II) Salts in the Samarium Barbier Reaction

Dhandapani V. Sadasivam, Kimberly A. Choquette, Robert A. Flowers II
Department of Chemistry, Lehigh University

A straightforward procedure for the preparation of samarium diiodide (SmI₂) in THF is described. The role of two main additives namely hexamethylphosphoramide (HMPA) and Ni(acac)₂ in Sm mediated reactions is demonstrated in the Sm-Barbier reaction.

Bringing the Visible Universe into Focus with Robo-AO

Christoph Baranec^{1, 2}, Reed Riddle¹, Nicholas M. Law³, A.N. Ramaprakash⁴, Shriharsh P. Tendulkar², Khanh Bui¹, Mahesh P. Burse⁴, Pravin Chordia⁴, Hillol K. Das⁴, Jack T.C. Davis¹, Richard G. Dekany¹, Mansi M. Kasliwal⁵, Shrinivas R. Kulkarni^{1, 2}, Timothy D. Morton², Eran O. Ofek⁶, Sujit Punnadi^4
1Caltech Optical Observatories, California Institute of Technology, ²Department of Astronomy, California Institute of Technology, ³Dunlap Institute for Astronomy and Astrophysics, University of Toronto, ⁴Inter-University Centre for Astronomy & Astrophysics, ⁵Observatories of the Carnegie Institution for Science, ⁶Benoziyo Center for Astrophysics, Weizmann Institute of Science

Light from astronomical objects must travel through the earth's turbulent atmosphere before it can be imaged by ground-based telescopes. To enable direct imaging at maximum theoretical angular resolution, advanced techniques such as those employed by the Robo-AO adaptive-optics system must be used.

Trajectory Data Analyses For Pedestrian Space-time Activity Study

Feng Qi¹, Fei Du^2
1School of Environmental and Life Sciences, Kean University, ²Department of Geography, University of Wisconsin-Madison

A suite of spatiotemporal processing methods are presented to analyze human trajectory data, such as that collected using a GPS device, for the purpose of modeling pedestrian space-time activities.

Murine Fetal Echocardiography

Gene H. Kim
Department of Medicine, Section of Cardiology, Institute for Cardiovascular Research, University of Chicago

Fetal and perinatal death is a common feature when studying genetic alterations affecting cardiac development. High-frequency ultrasound imaging has improved 2-D resolution and can provide excellent information on early cardiac development and is an ideal method to detect the impact on cardiac structure and function prior to death.