Abstract
The distribution in paraffin fixed human tissues of a carbohydrate antigen defined by two monoclonal antibodies raised against human granulocytes has been studied by means of an immunoperoxidase technique. In addition to granulocytes, the antigen has been detected in adult tissues on identifiable cell types of the stomach, kidney, adrenal medulla, and brain and on the mucins of the gastrointestinal tract and other secretions. In fetal tissue, epithelial cells of the alimentary tract, lung, brain, and kidney express the antigen. Adenocarcinoma of the colon, stomach, breast, and lung are stained strongly, as are other types of lung cancer. The monoclonal antibodies give a staining pattern similar but not identical to other monoclonal antibodies raised against granulocytes or neoplastic cell lines which recognise the antigen 3-fucosyl N-acetyllactosamine. The use of antibodies against this oncofetal antigen in the study of differentiation and as tumour markers is discussed.