A preparation of bacterial outer membrane with osmium tetroxide and uranyl acetate co-stain enables improved structural determination by transmission electron microscopy
Aadil Sheikh, Bernd Zechmann, Christie M. Sayes, Joseph H. Taube, K. Leigh Greathouse
Abstract
Biological nanoparticles, such as bacterial outer membrane vesicles (OMVs), are routinely characterized through transmission electron microscopy (TEM). In this study, we report a novel method to prepare OMVs for TEM imaging. To preserve vesicular shape and structure, we developed a dual fixation protocol involving osmium tetroxide incubation prior to negative staining with uranyl acetate. Combining osmium tetroxide with uranyl acetate resulted in preservation of sub-50 nm vesicles and improved morphological stability, enhancing characterization of lipid-based nanoparticles by TEM.
Topics & Concepts
Uranyl acetateOsmium tetroxideOsmiumUranylTransmission electron microscopyVesicleChemistryStainingMembraneNegative stainNuclear chemistryElectron microscopeChemical engineeringMaterials scienceNanotechnologyBiochemistryOrganic chemistryBiologyIonPhysicsGeneticsEngineeringOpticsRutheniumCatalysisBacterial Infections and VaccinesStreptococcal Infections and TreatmentsLipid Membrane Structure and Behavior