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Cell Death: The termination of the cell's ability to carry out vital functions such as metabolism, growth, reproduction, responsiveness, and adaptability.

An Introduction to Cell Death

JoVE 5649

Necrosis, apoptosis, and autophagic cell death are all manners in which cells can die, and these mechanisms can be induced by different stimuli, such as cell injury, low nutrient levels, or signaling proteins. Whereas necrosis is considered to be an “accidental” or unexpected form of cell death, evidence exists that apoptosis and autophagy are both programmed and “planned” by cells.In this introductory video, JoVE highlights key discoveries pertaining to cell death, including recent work done in worms that helped identify genes involved in apoptosis. We then explore questions asked by scientists studying cell death, some of which look at different death pathways and their interactions. Finally, several methods to assess cell death are discussed, and we note how researchers are applying these techniques in their experiments today.


 Cell Biology

Annexin V and Propidium Iodide Labeling

JoVE 5650

Staining with annexin V and propidium iodide (PI) provides researchers with a way to identify different types of cell death—either necrosis or apoptosis. This technique relies on two components. The first, annexin V, is a protein that binds certain phospholipids called phosphatidylserines, which normally occur only in the inner, cytoplasm-facing leaflet of a cell’s membrane, but become “flipped” to the outer leaflet during the early stages of apoptosis. The second component is the DNA-binding dye molecule PI, which can only enter cells when their membranes are ruptured—a characteristic of both necrosis and late apoptosis.This video article begins with a review of the concepts behind annexin V and PI staining, and emphasizes how differential patterns of staining can be used to distinguish between cells progressing down different death pathways. We then review a generalized protocol for this technique, followed by a description of how researchers are currently using annexin V and PI staining to better understand cell death.


 Cell Biology

The TUNEL Assay

JoVE 5651

One of the hallmarks of apoptosis is the nuclear DNA fragmentation by nucleases. These enzymes are activated by caspases, the family of proteins that execute the cell death program. TUNEL assay is a method that takes advantage of this feature to detect apoptotic cells. In this assay, an enzyme called terminal deoxynucleotidyl transferase catalyzes the addition of dUTP nucleotides to the free 3’ ends of fragmented DNA. By using dUTPs that are labeled with chemical tags that can produce fluorescence or color, apoptotic cells can be specifically identified. JoVE’s video on the TUNEL assay begins by discussing how this technique can be used to detect apoptotic cells. We then go through a general protocol for performing TUNEL assays on tissue sections and visualizing the results using fluorescence microscopy. Finally, several applications of the assay to current research will be covered.


 Cell Biology

An Introduction to Caenorhabditis elegans

JoVE 5103

Caenorhabditis elegans is a microscopic, soil-dwelling roundworm that has been powerfully used as a model organism since the early 1970’s. It was initially proposed as a model for developmental biology because of its invariant body plan, ease of genetic manipulation and low cost of maintenance. Since then C. elegans has rapidly grown in popularity and is now utilized in numerous research endeavors, from studying the forces at work during locomotion to studies of neural circuitry. This video provides an overview of basic C. elegans biology, a timeline of the many milestones in its short but storied history, and finally a few exciting applications using C. elegans as a model organism.


 Biology I

Histological Sample Preparation for Light Microscopy

JoVE 5039

Histology is the study of cells and tissues, which is typically aided by the use of a light microscope. The preparation of histological samples can vary greatly based on the inherent properties of the samples such as size and hardness as well as expected post-processing which includes planned staining techniques or other down-stream applications. As described in this video, specimen preparation typically begins with a fixation procedure to prevent degradation of the sample by naturally occurring enzymes that are released by the cells upon death. Once fixed, samples are placed into an embedding medium that is able to sufficiently support the sample. Most commonly this is paraffin wax, but other materials such as a glycerin based freezing medium and agars are also used to surround the sample during sectioning. Sectioning then takes place on a microtome or other cutting device that allows the user to shave the sample into thin slices ranging from a few microns to a few millimeters in thickness. Once cut, sections are mounted on a glass slide and stained to bring out specific features of the sample before being imaged on a microscope.


 General Laboratory Techniques

Bacterial Growth Curve Analysis and its Environmental Applications

JoVE 10100

Source: Laboratories of Dr. Ian Pepper and Dr. Charles Gerba - Arizona University
Demonstrating Author: Luisa Ikner

Bacteria are among the most abundant life forms on Earth. They are found in every ecosystem and are vital for everyday life. For example, bacteria affect what people eat, drink, and breathe, and there are actually more bacterial cells within a person’s body than mammalian cells. Because of the importance of bacteria, it is preferable to study particular species of bacteria in the laboratory. To do this, bacteria are grown under controlled conditions in pure culture, meaning that only one type of bacterium is under consideration. Bacteria grow quickly in pure culture, and cell numbers increase dramatically in a short period of time. By measuring the rate of cell population increase over time, a “growth curve” to be developed. This is important when aiming to utilize or inoculate known numbers of the bacterial isolate, for example to enhance plant growth, increase biodegradation of toxic organics, or produce antibiotics or other natural products at an industrial scale.


 Environmental Microbiology

An Introduction to Saccharomyces cerevisiae

JoVE 5081

Saccharomyces cerevisiae (commonly known as baker’s yeast) is a single-celled eukaryote that is frequently used in scientific research. S. cerevisiae is an attractive model organism due to the fact that its genome has been sequenced, its genetics are easily manipulated, and it is very easy to maintain in the lab. Because many yeast proteins are similar in sequence and function to those found in other organisms, studies performed in yeast can help us to determine how a particular gene or protein functions in higher eukaryotes (including humans). This video provides an introduction to the biology of this model organism, how it was discovered, and why labs all over the world have selected it as their model of choice. Previous studies performed in S. cerevisiae that have contributed to our understanding of important cellular processes such as the cell cycle, aging, and cell death are also discussed. Finally, the video describes some of the many ways in which yeast cells are put to work in modern scientific research, including protein purification and the study of DNA repair mechanisms and other cellular processes related to Alzheimer’s and Parkinson’s diseases.


 Biology I

Flow Cytometric Detection of Newly-Formed Breast Cancer Stem Cell-like Cells After Apoptosis Reversal

1School of Life Sciences, Chinese University of Hong Kong, 2State Key Laboratory of Agrobiotechnology, Chinese University of Hong Kong, 3Key Laboratory for Regenerative Medicine, Ministry of Education, Chinese University of Hong Kong, 4Centre for Novel Biomaterials, Chinese University of Hong Kong

Video Coming Soon

JoVE 58642


 JoVE In-Press

Protein Kinase C-delta Inhibitor Peptide Formulation Using Gold Nanoparticles

1Latner Thoracic Surgery Research Laboratories, Toronto General Hospital Research Institute, University Health Network, 2Respiratory Medicine Research Laboratory, Institute of Translation Medicine, Shanghai General Hospital, Shanghai Jiaotong University, 3Institute of Medical Science, Faculty of Medicine, University of Toronto

Video Coming Soon

JoVE 58741


 JoVE In-Press

Polyethyleneimine-coated Iron Oxide Nanoparticles As a Vehicle for the Delivery of Small Interfering RNA to Macrophages In Vitro and In Vivo

1Key Laboratory of Ministry of Education for Developmental Genes & Human Diseases, Institute of Life Sciences, Southeast University, 2State Key Laboratory of Bioelectronics, Jiangsu Key Laboratory for Biomaterials & Devices, School of Biological Science & Medical Engineering, Southeast University, 3Key Laboratory of Ministry of Education for Developmental Genes & Human Diseases, Medical School, Southeast University

Video Coming Soon

JoVE 58660


 JoVE In-Press

Multimodal Bioluminescent and Positronic-emission Tomography/Computational Tomography Imaging of Multiple Myeloma Bone Marrow Xenografts in NOG Mice

1Greater Los Angeles Veteran Administration Healthcare System, 2San Diego Veterans Administration Healthcare System, 3University of California, Los Angeles, 4Perkin Elmer

Video Coming Soon

JoVE 58056


 JoVE In-Press

Isolation of Extracellular Vesicles from Murine Bronchoalveolar Lavage Fluid Using an Ultrafiltration Centrifugation Technique

1Department of Medicine, Division of Pulmonary and Critical Care, Women's Guild Lung Institute, Cedars-Sinai Medical Center, 2Department of Biomedical Sciences, Cedars-Sinai Medical Center, 3Department of Medicine, Smidt Heart Institute, Cedars-Sinai Medical Center

Video Coming Soon

JoVE 58310


 JoVE In-Press

Generation of Cationic Nanoliposomes for the Efficient Delivery of In Vitro Transcribed Messenger RNA

1Department of Thoracic and Cardiovascular Surgery, Clinical Research Laboratory, University Medical Center, 2Atherothrombosis and Vascular Biology, Baker Heart & Diabetes Institute, 3Department of Medicine, Monash University

Video Coming Soon

JoVE 58444


 JoVE In-Press

Targeted and Selective Treatment of Pluripotent Stem Cell-derived Teratomas Using External Beam Radiation in a Small-animal Model

1Stanford Cardiovascular Institute, Stanford University School of Medicine, 2Department of Medicine, Division of Cardiology, Stanford University School of Medicine, 3Medical Service, Cardiology Section, Veteran Affairs Palo Alto Health Care System, 4Department of Pathology, Stanford University School of Medicine, 5Department of Radiology, Molecular Imaging Program, Stanford University School of Medicine, 6Peking University Shenzhen Health Science Institute, 7Department of Radiation Oncology, Stanford University School of Medicine

Video Coming Soon

JoVE 58115


 JoVE In-Press

Unicellular Selection of Living Cells in Liquid Medium Using Laser Microdissection and a Pressure Catapulting System

1U1165, Université Paris-Diderot, INSERM, 2Pôle de Recherches Sino-Français en Science du Vivant et Génomique, Shanghai Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, 3Laboratoire de Pathologie, AP-HP-Hôpital Saint-Louis, 4Service d’Oncologie Médicale, AP-HP-Hôpital Avicenne, 5Université Paris 13

Video Coming Soon

JoVE 58234


 JoVE In-Press

Isolation of Adult Spinal Cord Nuclei for Massively Parallel Single-nucleus RNA Sequencing

1Spinal Circuits and Plasticity Unit, National Institute of Neurological Disorders and Stroke, 2Bioinformatics Section, Information Technology Program, National Institute of Neurological Disorders and Stroke, 3Laboratory of Cochlear Development, National Institute on Deafness and Other Communication Disorders, 4Single Cell Analysis Facility, Frederick National Laboratory

JoVE 58413


 Neuroscience

Using 22C3 Anti-PD-L1 Antibody Concentrate on Biopsy and Cytology Samples from Non-small Cell Lung Cancer Patients

1Laboratory of Clinical and Experimental Pathology, Pasteur Hospital, Hospital University Federation OncoAge, Université Côte d’Azur, 2Institute for Research on Cancer and Aging in Nice (Inserm U1081 and CNRS 7284), Université Côte d’Azur, 3Hospital-Integrated Biobank (BB-0033-00025), Pasteur Hospital, Université Côte d’Azur

JoVE 58082


 Cancer Research

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