Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital 1 article published in JoVE Genetics In Vivo CRISPR/Cas9 Screening to Simultaneously Evaluate Gene Function in Mouse Skin and Oral Cavity Sampath Kumar Loganathan1, Ahmad Malik1,2, Ellen Langille1,2, Chen Luxenburg3, Daniel Schramek1,2 1Centre for Molecular and Systems Biology, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, 2Department of Molecular Genetics, University of Toronto, 3Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University Here we describe a rapid and direct in vivo CRISPR/Cas9 screening methodology using ultrasound-guided in utero embryonic lentiviral injections to simultaneously assess functions of several genes in the skin and oral cavity of immunocompetent mice.