The document details the Caco-2 cell permeability assay, outlining the characteristics, advantages, and limitations of Caco-2 cell monolayers derived from human colorectal adenocarcinoma. It provides a comprehensive guide on cell culture materials, cultivation procedures, TEER measurement, permeability assay protocols, and Papp calculations. This assay is crucial for assessing drug absorption and transport efficiency in research and pharmaceutical applications.