Universidade Federal do Rio de Janeiro View Institution's Website 10 articles published in JoVE Biochemistry Preparation of Hard Palm Seeds for Matrix-Assisted Laser Desorption/Ionization-Imaging Mass Spectrometry Analysis Gabriel R. Martins*1,2, Felipe L. Brum*1,2,3, Davi Marconi Miranda Carvalho da Silva*1,2, Livia C. Barbosa3, Ronaldo Mohana-Borges3, Ayla Sant'Ana da Silva1,2 1Laboratório de Biocatálise (LABIC), Instituto Nacional de Tecnologia, 2Departamento de Bioquímica, Instituto de Química, Universidade Federal do Rio de Janeiro, 3Centro de Espectrometria de Massas de Biomoléculas, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro This protocol aimed to describe detailed guidance on the preparation of hard seed sample sections with low water content for MALDI-IMS analysis, maintaining analytes' original distribution and abundance and providing high-quality signal and spatial resolution. Biochemistry Assessing Mitochondrial Function in Sciatic Nerve by High-Resolution Respirometry Marcos A. Formiga-Jr1, Juliana Camacho-Pereira1 1Instituto de Bioquímica Médica Leopoldo de Meis, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro High-resolution respirometry coupled to fluorescence sensors determines mitochondrial oxygen consumption and reactive oxygen species (ROS) generation. The present protocol describes a technique to assess mitochondrial respiratory rates and ROS production in the permeabilized sciatic nerve. Neuroscience Visualizing Shifts on Neuron-Glia Circuit with the Calcium Imaging Technique Matheus H. Tempone1, Hercules R. Freitas2, Clarissa S. Schitine3, Ricardo A. de Melo Reis1 1Laboratory of Neurochemistry, Institute of Biophysics Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, 2Laboratory of Neuroenergetics and Inborn Errors of Metabolism, Institute of Medical Biochemistry Leopoldo de Meis, Universidade Federal do Rio de Janeiro, 3Laboratory of Neurochemistry and Cell Biology, Institute of Life Sciences, Universidade Federal da Bahia Cell calcium imaging is a versatile methodology to study dynamic signaling of individual cells, on mixed populations in culture or even on awakened animals, based on the expression of calcium-permeable channels/receptors that gives unique functional signatures. Biology Quantitative Analysis of Viscoelastic Properties of Red Blood Cells Using Optical Tweezers and Defocusing Microscopy Lucas Barreto*1,2, Fran Gomez*1,2, Pedro S. Lourenço1,2, Douglas G. Freitas1,2, Juliana Soares1,3, Clemilson Berto-Junior4,5, Ubirajara Agero6, Nathan B. Viana1,2, Bruno Pontes1,2,3,7 1Centro Nacional de Biologia Estrutural e Bioimagem - CENABIO, Universidade Federal do Rio de Janeiro, 2Instituto de Física, Programa de Pós-graduação Multidisciplinar em Física Aplicada, Universidade Federal do Rio de Janeiro, 3Instituto de Biofísica Carlos Chagas Filho, Programa de Pós-graduação em Ciências Biológicas Biofísica, Universidade Federal do Rio de Janeiro, 4Faculdade de Farmácia, Universidade Federal do Rio de Janeiro - Campus Macaé, 5Faculdade de Medicina, Programa de Pós-Graduação em Endocrinologia, Universidade Federal do Rio de Janeiro, 6Instituto de Ciências Exatas, Departamento de Física, Universidade Federal de Minas Gerais, 7Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro Here, an integrated protocol based on optical tweezers and defocusing microscopy is described to measure the rheological properties of cells. This protocol has wide applicability in studying the viscoelastic properties of erythrocytes under variable physio-pathological conditions. Neuroscience Full-Circle Cauterization of Limbal Vascular Plexus for Surgically Induced Glaucoma in Rodents Rafael Lani-Louzada1, Carla Andreia Abreu1, Victor G. Araújo1, Mariana S. Dias1, Hilda Petrs-Silva1, Rafael Linden1 1Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro The goal of this protocol is to characterize a novel model of glaucomatous neurodegeneration based on 360° thermic cauterization of limbal vascular plexus, inducing subacute ocular hypertension. Immunology and Infection Three-Dimensional Imaging of the Vertebral Lymphatic Vasculature and Drainage using iDISCO+ and Light Sheet Fluorescence Microscopy Laurent Jacob*1, Jose Brito*1,2, Jean-Leon Thomas1,3 1Université Pierre et Marie Curie Paris, Sorbonne Université, Institut du Cerveau et de la Moelle Epinière, 2Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, 3Department of Neurology, Yale University School of Medicine A protocol is presented combining tissue clearing with light sheet fluorescence microscopy (LSFM) to obtain three-dimensional and cellular resolution images of the lymphatic vessels and lymph nodes (LNs) collecting the cerebrospinal fluid (CSF) and spinal epidural fluid. Biochemistry Lipid Index Determination by Liquid Fluorescence Recovery in the Fungal Pathogen Ustilago Maydis Lucero Romero-Aguilar*1,2, Mónica Montero-Lomeli*3, Juan Pablo Pardo2, Guadalupe Guerra- Sánchez1 1Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, 2Facultad de Medicina, Universidad Nacional Autónoma de México, 3Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro Here, we describe a protocol to obtain the lipid droplet index (LD index) to study the dynamics of triacylglycerols in cells cultured in high-throughput experiments. The LD index assay is an easy and reliable method that uses BODIPY 493/503. This assay does not need dispendious lipid extraction or microscopy analysis. Biology Analysis of Pluripotent Stem Cells by using Cryosections of Embryoid Bodies Ismael C. Gomes*1, Mariana Acquarone*1, Renata de Moraes Maciel*1, Rafael Bierig Erlich1, Stevens K. Rehen1 1Laboratório Nacional de Céulas-Tronco Embrionárias (LaNCE), Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro (UFRJ), Brazil Pluripotent stem cells growing in suspension differentiate into embryoid bodies (EBs). Here we demonstrate how to obtain high quality EB cryosections useful for studying cellular and molecular aspects of embryogenesis, while preserving their organization as aggregates. Biology Murine Model for Parkinson's Disease: from 6-OH Dopamine Lesion to Behavioral Test Fabio S.L. da Conceição1, Stacie Ngo-Abdalla1, Jean-Christophe Houzel1, Stevens K. Rehen1 1Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Brasil Parkinson disease is caused by loss of dopaminergic innervation to the striatum, which can be experimentally induced by 6-OH-dopamine. We describe how to perform a stereotaxic lesion and to monitor apomorphine-induced rotational behavior in mice. This model is useful and reliable for testing new therapies for Parkinson disease. Biology Chromosomal Spread Preparation of Human Embryonic Stem Cells for Karyotyping Priscila B. Campos1, Rafaela C. Sartore1, Stacie N. Abdalla1, Stevens K. Rehen1 1Institute of Biomedical Sciences, Federal University of Rio De Janeiro-UFRJ Karyotyping is a simple and useful technique widely used for detecting genetic alterations. Here we describe a step by step protocol for chromosome spread preparation of human embryonic stem cells for monitoring the chromosomal status of these cells maintained in culture.