Ministry of Fisheries and Livestock 1 article published in JoVE Bioengineering Agarose-based Tissue Mimicking Optical Phantoms for Diffuse Reflectance Spectroscopy Afrina Mustari*1, Izumi Nishidate*1, Md. Abdul Wares1,6, Takaaki Maeda2, Satoko Kawauchi3, Shunichi Sato3, Manabu Sato4, Yoshihisa Aizu5 1Graduate School of Bio-application & Systems Engineering, Tokyo University of Agriculture & Technology, 2Department of Mechanical Engineering, Kushiro National College of Technology, 3Division of Bioinformation and Therapeutic Systems, National Defense Medical College Research Institute, 4Graduate School of Science and Engineering, Yamagata University, 5College of Design and Manufacturing Technology, Muroran Institute of Technology, 6Department of Livestock Services, Ministry of Fisheries and Livestock, Government of Bangladesh Here, we demonstrate how agarose-based tissue-mimicking optical phantoms are made and how their optical properties are determined using a conventional optical system with an integrating sphere.