Abstract
Detection of a common antigen of Gram-negative bacteria was attempted with immunohistochemistry on formalin fixed paraffin sections. An anti-lipopolysaccharide (LPS) rabbit serum widely reacted with gramnegative bacterial antigens in the lesions. In addition, the anti-LPS serum was reactive with the bacterial antigens in the cytoplasm of infiltrated macrophages and giant cells in fibrous tissues where the species specific antisera were not reactive.
