The CanAg CA19-9 EIA is based on a mouse monoclonal antibody, C192, highly specific for the sialyl Lewisa epitope, also known as CA19-9 antigen1.
In adults, the epitope is typically expressed in trace amounts on mucosal cells of gastrointestinal epithelia. In patients with malignant disease, the epitope may appear associated with high molecular weight mucin in blood. Assays for CA19-9 are frequently used to monitor gastrointestinal malignancies such as pancreatic, gall bladder, gastric, and colorectal cancers