Human placental laminin purified without the use of proteases promotes similar levels of cell attachment to murine EHS laminin. The major HT1080 cell binding site of human placental laminin is thermally less labile than that of EHS laminin. Monoclonal antibody GOH3, which recognises the integrin alpha-6 subunit, inhibits HT1080 and B16 cell attachment to EHS laminin but not to human placental laminin, indicating that the cells use different receptors to bind to these two types of laminin. Antibodies PIE6 and PIB5, which recognise the integrin alpha-2 and alpha-3 subunits respectively, do not affect HT1080 cell binding to either type of laminin.