Shizuoka University 2 articles published in JoVE Biology Functional Assessment of Intestinal Tight Junction Barrier and Ion Permeability in Native Tissue by Ussing Chamber Technique Wendy Hempstock1, Noriko Ishizuka1, Hisaysohi Hayashi1 1Laboratory of Physiology, Graduate School of Nutritional and Environmental Sciences, University of Shizuoka Intestinal epithelium confers not only nutrient absorption but protection against noxious substances. The apical-most epithelial intercellular junction, i.e., the tight junction, regulates paracellular solute and ion permeability. Here, a protocol for the preparation of mucosal sheets and assessment of the ion selectivity of tight junctions using Ussing chamber technique is described. Genetics High-Resolution Comparison of Bacterial Conjugation Frequencies Masaki Shintani1,2,3, Moriya Ohkuma3, Kazuhide Kimbara1 1Applied Chemistry and Biochemical Engineering Course, Department of Engineering, Graduate School of Integrated Science and Technology, Shizuoka University, 2Department of Bioscience, Graduated School of Science and Technology, Shizuoka University, 3Japan Collection of Microorganisms, RIKEN BioResource Research Center With an aim to understand the behaviors of various bacterial conjugative DNA elements under different conditions, we describe a protocol for detecting differences in conjugation frequency, with high resolution, to estimate how efficiently the donor bacterium initiates conjugation.