JoVE Clinical and Translational Medicine
1Umeå Centre for Molecular Medicine, Umeå University, 2Cell Transplant Center, Diabetes Research Institute, University of Miami,, 3EMBL-CRG Systems Biology Program, Centre for Genomic Regulation, Catalan Institute of Research and Advanced Studies, 4Dept. of Computing Science, Umeå University
We describe the adaptation of optical projection tomography (OPT)1 to imaging in the near infrared spectrum, and the implementation of a number of computational tools. These protocols enable assessments of pancreatic β-cell mass (BCM) in larger specimens, increase the multichannel capacity of the technique and increase the quality of OPT data.
Published January 12, 2013. Keywords: Medicine, Biomedical Engineering, Cellular Biology, Molecular Biology, Biophysics, Pancreas, Islets of Langerhans, Diabetes Mellitus, Imaging, Three-Dimensional, Optical Projection Tomography, Beta-cell Mass, Near Infrared, Computational Processing
1Department of Medicine, University of Chicago
The following protocol outlines the process of pancreatic dissection for virtual slice imaging, and the subsequent quantification of all GFP-tagged beta-cells in the entire pancreas.
Published June 7, 2010. Keywords: Cellular Biology, beta-cells, islets, mouse, pancreas
1Division of Nutritional Sciences, Cornell University, 2Field of Biochemistry, and Molecular Cell Biology, Cornell University
Metabolite profiling has been a valuable asset in the study of metabolism in health and disease. Utilizing normal-phased liquid chromatography coupled to high-resolution mass spectrometry with polarity switching and a rapid duty cycle, we describe a protocol to analyze the polar metabolic composition of biological material with high sensitivity, accuracy, and resolution.
Published May 27, 2014. Keywords: Chemistry, high-resolution mass spectrometry, metabolomics, positive/negative switching, low mass calibration, Orbitrap
1Department of Biology, The University of Mississippi
Microplate based procedures are described for the colorimetric or fluorometric analysis of extracellular enzyme activity. These procedures allow for the rapid assay of such activity in large numbers of environmental samples within a manageable time frame.
Published October 1, 2013. Keywords: Environmental Sciences, Environmental Monitoring, Ecological and Environmental Processes, Environmental Microbiology, Ecology, extracellular enzymes, freshwater microbiology, soil microbiology, microbial activity, enzyme activity
1Centers for Cancer Pharmacology and Excellence in Environmental Toxicology, University of Pennsylvania, 2Department of Pharmacology, University of Pennsylvania
This protocol will demonstrate the extraction and analysis of free and esterified bioactive fatty acids from cells. Fatty acids are accurately quantified using stable isotope dilution, chiral liquid chromatography, electron capture atmospheric chemical ionization multiple reaction monitoring mass spectrometry (SID-LC-ECAPCI-MRM/MS).
Published November 17, 2011. Keywords: Bioengineering, lipids, extraction, stable isotope dilution, chiral chromatography, electron capture, mass spectrometry
JoVE Immunology and Infection
1Undergraduate Program, Rice University, 2Proteomics Facility, Department of Pathology, University of Texas MD Anderson Cancer Center, 3Department of Melanoma Medical Oncology, University of Texas MD Anderson Cancer Center, 4University of Texas Graduate School of Biological Sciences at Houston
A specific and sensitive method to gain insight into the expression profile of glycosphingolipid antigens in immune organs and cells is described. The method takes advantage of the ion trap mass spectrometry allowing step-wise fragmentation of glycosphingolipid molecules for structural analysis in comparison to chemically synthesized standards.
Published April 16, 2013. Keywords: Immunology, Biochemistry, Molecular Biology, Cellular Biology, Structural Biology, Medicine, Genetics, Proteomics, Proteins, Glycomics, Functional glycomics, glycosphingolipids, GSLs, antigens, natural killer T cells, MALDI-TOF mass spectrometry, LTQ ion trap mass spectrometer, mass spectrometry, glycolipids, lipids
JoVE Clinical and Translational Medicine
1Department of Pediatrics, Indiana University School of Medicine, 2Department of Cellular & Integrative Physiology, Indiana University School of Medicine
This protocol allows one to identify factors that modulate functional beta cell mass to find potential therapeutic targets for the treatment of diabetes. The protocol consists of a streamlined method to assess islet replication and beta cell function in isolated rat islets following manipulation of gene expression with adenoviruses.
Published June 25, 2012. Keywords: Medicine, Physiology, beta cell, gene expression, islet, diabetes, insulin secretion, proliferation, adenovirus, rat
1Center for Applied Proteomics and Molecular Medicine, George Mason University, 2Ceres Nanosciences
Several pathological biomarkers cannot be easily detected by current techniques because of their low concentration in biological fluids, the presence of degrading enzymes, and large amounts of high molecular weight proteins. Chemically functionalized hydrogel nanoparticles can harvest, preserve and concentrate low abundance proteins enabling the detection of previously undetectable biomarkers.
Published August 7, 2014. Keywords: Bioengineering, biomarker, hydrogel, low abundance, mass spectrometry, nanoparticle, plasma, protein, urine
1Department of Neurology, David Geffen School of Medicine, 2Molecular Biology Institute, University of California, Los Angeles, 3Brain Research Institute, University of California, Los Angeles
Aptamers are short ribo-/deoxyribo-oligonucleotides selected by in-vitro evolution methods based on affinity for a specific target. Aptamers are molecular recognition tools with versatile therapeutic, diagnostic, and research applications. We demonstrate methods for selection of aptamers for amyloid β-protein, the causative agent of Alzheimer's disease.
Published May 13, 2010. Keywords: Neuroscience, Cellular Biology, Aptamer, RNA, amyloid β-protein, oligomer, amyloid fibrils, protein assembly
1Banting and Best Department of Medical Research, Donnelly Centre, University of Toronto, 2Deparment of Biochemistry, Research and Innovation Centre, University of Regina, 3Department of Medical Genetics and Microbiology, University of Toronto
Affinity purification of tagged proteins in combination with mass spectrometry (APMS) is a powerful method for the systematic mapping of protein interaction networks and for investigating the mechanistic basis of biological processes. Here, we describe an optimized sequential peptide affinity (SPA) APMS procedure developed for the bacterium Escherichia coli that can be used to isolate and characterize stable multi-protein complexes to near homogeneity even starting from low copy numbers per cell.
Published November 12, 2012. Keywords: Genetics, Molecular Biology, Medicine, Biochemistry, Microbiology, affinity purification, Escherichia coli, gram-negative bacteria, cytosolic proteins, SPA-tagging, homologous recombination, mass spectrometry, protein interaction, protein complex