The antigen is CD54, the antibody recognizes an epitope on domain 1 of the molecule as tested on transfectants. Biochemistry: Clone 1304 stains a 95kD single chain integral membrane glycoprotein. The epitope is stable against acetone or paraformaldehyde fixation. ICAM 1 also functions as a rhinovirus receptor. Antigen distribution: Isolated cells: ICAM-1 expression can be induced on endothelial cells by in vitro stimulation with IL-1, TNF-alpha and IFN-gamma. Tissue sections: In inflamed lesions, the antibody reacts with stimulated endothelial cells, epithelial cells and fibroblasts and with haemopoietic cells such as macrophages, dendritic cells in Peyer's patches, lymph nodes and tonsils. Specificity: Human: CD54. Other: not tested.