INCELL has successfully completed innovative work establishing several unique human epithelial cell lines of normal small intestine. These cells have been partially characterized and preliminary transport studies suggest that they have characteristics more similar to the small intestine than the Caco-2 cell model. In Phase II, further characterization of these cells will be done. We will examine site-specific differences between the cell lines and determine if passage number or differentiation state effect cellular function. Reproducibility studies of the transport systems will lead to development of a commercial product that can be shipped in a ready to use format. The proposed transport models will be designed to be superior to the current model and serve as the new gold standard for intestinal cell line testing. The addition of these unique transport models, cell cultures and RNA and protein extracts from these cell lines will expand INCELL's products and services capabilities and allow INCELL to capture the majority share of the current markets. ? ?