Weizmann Institute of Science 6 articles published in JoVE Biology Visualization of Organelles In Situ by Cryo-STEM Tomography Peter Kirchweger1, Debakshi Mullick1, Sharon Grayer Wolf2, Michael Elbaum1 1Department of Chemical and Biological Physics, Weizmann Institute of Sciences, 2Department of Chemical Research Support, Weizmann Institute of Sciences Cryo-STEM tomography provides a means to visualize organelles of intact cells without embedding, sectioning, or other invasive preparations. The 3D resolution obtained is currently in the range of a few nanometers, with a field of view of several micrometers and an accessible thickness in the order of 1 µm. Developmental Biology Ex Utero Culture of Mouse Embryos from Pregastrulation to Advanced Organogenesis Alejandro Aguilera-Castrejon1, Jacob H. Hanna1 1Department of Molecular Genetics, Weizmann Institute of Science An enhanced platform for whole-embryo culture allows continuous and robust ex utero development of postimplantation mouse embryos for up to six days, from pregastrulation stages until advanced organogenesis. In this protocol, we detail the standard procedure for successful embryo culture using static plates and rotating bottle systems. Behavior Longitudinal Two-Photon Imaging of Dorsal Hippocampal CA1 in Live Mice Alessandro F. Ulivi1, Tim P. Castello-Waldow1, Ghabiba Weston1,2, Long Yan3, Ryohei Yasuda3, Alon Chen1,4, Alessio Attardo1 1Dept. of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, 2Graduate School of Systemic Neurosciences, Ludwig Maximilians University, 3Max Planck Florida Institute for Neuroscience, 4Dept. of Neurobiology, Weizmann Institute of Science This method describes a chronic preparation that allows optical access to the hippocampus of living mice. This preparation can be used to perform longitudinal optical imaging of neuronal structural plasticity and activity-evoked cellular plasticity over a period of several weeks. Developmental Biology Generation of Human Primordial Germ Cell-like Cells at the Surface of Embryoid Bodies from Primed-pluripotency Induced Pluripotent Stem Cells Shino Mitsunaga1, Keiko Shioda1, Kurt J. Isselbacher1, Jacob H. Hanna2, Toshi Shioda1 1Center for Cancer Research, Massachusetts General Hospital, 2Department of Molecular Genetics, Weizmann Institute of Science Primordial germ cells (PGCs) are common precursors of both sperm and eggs. Human embryonic PGCs are specified from pluripotent epiblast cells through interactions of cytokines. Here, we describe a 13-day protocol of inducing human cells transcriptomally resembling PGCs at the surface of embryoid bodies from primed-pluripotency induced pluripotent stem cells. Biology Method for Labeling Transcripts in Individual Escherichia coli Cells for Single-molecule Fluorescence In Situ Hybridization Experiments Rinat Arbel-Goren1, Yonatan Shapira1, Joel Stavans1 1Department of Physics of Complex Systems, Weizmann Institute of Science This manuscript describes a method for labeling individual messenger RNA (mRNA) transcripts with fluorescently-labeled DNA probes, for use in single-molecule fluorescence in situ hybridization (smFISH) experiments in E. coli. smFISH is a visualization method that allows the simultaneous detection, localization, and quantification of single mRNA molecules in fixed individual cells. Neuroscience External Excitation of Neurons Using Electric and Magnetic Fields in One- and Two-dimensional Cultures Shani Stern1, Assaf Rotem2, Yuri Burnishev3, Eyal Weinreb3, Elisha Moses3 1Laboratory of Genetics, The Salk Institute for Biological Studies, 2Department of Physics and SEAS, Harvard University, 3Department of Physics of Complex Systems, Weizmann Institute of Science Neuronal cultures are a good model for studying emerging brain stimulation techniques via their effect on single neurons or a population of neurons. Presented here are different methods for stimulation of patterned neuronal cultures by an electric field produced directly by bath electrodes or induced by a time-varying magnetic field.