Rensselaer Polytechnic Institute View Institution's Website 9 articles published in JoVE Cancer Research Non-Destructive Evaluation of Regional Cell Density Within Tumor Aggregates Following Drug Treatment Cassandra L. Roberge1, Ling Wang2, Margarida Barroso2, David T. Corr1 1Rensselaer Polytechnic Institute, 2Albany Medical College The present protocol develops an image-based technique for rapid, non-destructive, and label-free regional cell density and viability measurement within 3D tumor aggregates. Findings revealed a cell-density gradient, with higher cell densities in core regions than outer layers in developing aggregates and predominantly peripheral cell death in HER2+ aggregates treated with Trastuzumab. Biology Directly Measuring Forces Within Reconstituted Active Microtubule Bundles Jacob Palumbo*1, Ellinor Tai*1, Scott Forth1 1Department of Biological Sciences and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute Here, we present a protocol for reconstituting microtubule bundles in vitro and directly quantifying the forces exerted within them using simultaneous optical trapping and total internal reflection fluorescence microscopy. This assay allows for nanoscale-level measurement of the forces and displacements generated by protein ensembles within active microtubule networks. Bioengineering A Micropatterning Assay for Measuring Cell Chirality Haokang Zhang1,2, Kacey Ronaldson-Bouchard3, Gordana Vunjak-Novakovic3,4, Leo Q. Wan1,2,5,6 1Department of Biomedical Engineering, Rensselaer Polytechnic Institute, 2Center for Biotechnology & Interdisciplinary Studies, Rensselaer Polytechnic Institute, 3Department of Biomedical Engineering, Columbia University, 4Department of Medicine, Columbia University, 5Department of Biological Sciences, Rensselaer Polytechnic Institute, 6Center for Modeling, Simulation, and Imaging in Medicine, Rensselaer Polytechnic Institute We present a protocol for determining multicellular chirality in vitro, using the micropatterning technique. This assay allows for automatic quantification of the left-right biases of various types of cells and can be used for screening purposes. Biology Detection of Glycosaminoglycans by Polyacrylamide Gel Electrophoresis and Silver Staining Wells B. LaRiviere1,2, Xiaorui Han3,4, Kaori Oshima1, Sarah A. McMurtry1, Robert J. Linhardt3, Eric P. Schmidt1,5 1Department of Medicine, University of Colorado Anschutz Medical Campus, 2Medical Scientist Training Program, University of Colorado Anschutz Medical Campus, 3Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, 4Department of Health Sciences, Curtin University, 5Department of Medicine, Denver Health Medical Center This report describes techniques to isolate and purify sulfated glycosaminoglycans (GAGs) from biological samples and a polyacrylamide gel electrophoresis approach to approximate their size. GAGs contribute to tissue structure and influence signaling processes via electrostatic interaction with proteins. GAG polymer length contributes to their binding affinity for cognate ligands. Bioengineering Patterning Bioactive Proteins or Peptides on Hydrogel Using Photochemistry for Biological Applications Taylor B. Dorsey1,2,3, Alexander Grath1,2, Cancan Xu4, Yi Hong4, Guohao Dai1,2,3 1Department of Biomedical Engineering, Rensselaer Polytechnic Institute, 2Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, 3Department of Bioengineering, Northeastern University, 4Department of Bioengineering, University of Texas at Arlington In this method, we use photopolymerization and click chemistry techniques to create protein or peptide patterns on the surface of polyethylene glycol (PEG) hydrogels, providing immobilized bioactive signals for the study of cellular responses in vitro. Biology Combining Magnetic Sorting of Mother Cells and Fluctuation Tests to Analyze Genome Instability During Mitotic Cell Aging in Saccharomyces cerevisiae Melissa N. Patterson1, Patrick H. Maxwell1 1Department of Biological Sciences, Rensselaer Polytechnic Institute Mutation rates in young Saccharomyces cerevisiae cells measured through fluctuation tests are used to predict mutation frequencies for mother cells of different replicative ages. Magnetic sorting and flow cytometry are then used to measure actual mutation frequencies and age of mother cells to identify any deviations from predicted mutation frequencies. Bioengineering Human Cartilage Tissue Fabrication Using Three-dimensional Inkjet Printing Technology Xiaofeng Cui*1,2,3, Guifang Gao*2,4, Tomo Yonezawa5,6, Guohao Dai1 1Department of Biomedical Engineering, Rensselaer Polytechnic Institute, 2Stemorgan Inc., 3Institute of Advanced Study, Technical University of Munich, 4Institute of Virology, School of Medicine, Wuhan University, 5Department of Molecular and Experimental Medicine, The Scripps Research Institute, 6Research Institute for Biomedical Sciences, Tokyo University of Science The methods described in this paper show how to convert a commercial inkjet printer into a bioprinter with simultaneous UV polymerization. The printer is capable of constructing 3D tissue structure with cells and biomaterials. The study demonstrated here constructed a 3D neocartilage. Bioengineering Small and Wide Angle X-Ray Scattering Studies of Biological Macromolecules in Solution Li Liu1, Lauren Boldon1, Melissa Urquhart1, Xiangyu Wang1 1Department of Mechanical, Aerospace, and Nuclear Engineering, Rensselaer Polytechnic Institute The demonstration of the small and wide angle X-ray scattering (SWAXS) procedure has become instrumental in the study of biological macromolecules. Through the use of the instrumentation and procedures of specific angle methods and preparation, the experimental data from the SWAXS displays the atomic and nano-scale characterization of macromolecules. Neuroscience Recording Human Electrocorticographic (ECoG) Signals for Neuroscientific Research and Real-time Functional Cortical Mapping N. Jeremy Hill1, Disha Gupta1,2, Peter Brunner1,2, Aysegul Gunduz1,2, Matthew A. Adamo3, Anthony Ritaccio2, Gerwin Schalk1,2,4,5,6,7 1Wadsworth Center, New York State Department of Health, 2Department of Neurology, Albany Medical College, 3Department of Neurosurgery, Albany Medical College, 4Department of Neurosurgery, Washington University, 5Department of Biomed. Eng., Rensselaer Polytechnic Institute, 6Department of Biomed. Sci., State University of New York at Albany, 7Department of Elec. and Comp. Eng., University of Texas at El Paso We present a method for collecting electrocorticographic signals for research purposes from humans who are undergoing invasive epilepsy monitoring. We show how to use the BCI2000 software platform for data collection, signal processing and stimulus presentation. Specifically, we demonstrate SIGFRIED, a BCI2000-based tool for real-time functional brain mapping.