Oklahoma Children's Hospital 1 article published in JoVE Immunology and Infection Determining Intestinal Permeability Using Lucifer Yellow in an Apical-Out Enteroid Model Heather Liebe1, Camille Schlegel2, Xue Cai2, Alena Golubkova1, Tyler Leiva1, William L. Berry3, Catherine J. Hunter1 1 The present protocol outlines a method that utilizes lucifer yellow in an apical-out enteroid model to determine intestinal permeability. This method can be used to determine paracellular permeability in enteroids that model inflammatory bowel diseases such as necrotizing enterocolitis.