Cadherins are calcium dependent glycoproteins involved in homophilic cell-cell adhesion. To further elucidate the interaction between cadherins we have developed an immobilized peptide ELISA to quickly scan the extracellular domains of E-cadherin. Peptides displaying antigenic reactivity to anti-E-cadherin antibody are presumably on the surface and thus may be involved in cadherin-cadherin interaction. We have found three peptides from the EC-1 domain which are recognized by the anti-E-cadherin antibody. These peptides are in the two important regions of the EC-1 domain that was deduced from its secondary structure.