Comparative histo-morphologies of bison versus bovine RAJ from E. coli O157-negative animals. Immunofluorescence stained slides are shown at 10x magnification. Different fluorescent tags were used to detect each epithelial cell protein: Villin (green), Vimentin (green), Cytokeratin (orange-red), E-cadherein (green) and N-cadherin (red). Epithelial cell nuclei have blue fluorescence. C, columnar epithelium; S, stratified squamous epithelium; J, junction between columnar and stratified squamous epithelium; L, liver tissue section used in sample preparation. Arrows indicate representative regions of stained epithelial cell proteins.