MAb VU-11D1 reacts with MUC1, a large transmembrane glycoprotein expressed on the ductal surface of normal glandular epithelia. The dominant epitope of MAb VU-11D1 is the 7-mer TSAPDTR of the MUC1 tandem repeat as established with epitope fingerprinting. Theextra cellular domain of MUC1 largely consists of a highly conserved, O-glycosylated 20 amino acids tandem repeat which can occur 30-100 times per molecule depending on the length of the allele involved. In the vast majority of human carcinomas this protein is up regulated and poorly glycosylated and appears on the cell surface in a non-polarized fashion.
