ONE-STEP SANDWICH ENZYME-IMMUNOASSAY FOR HUMAN LAMININ USING MONOCLONAL-ANTIBODIES

A one-step sandwich enzyme immunoassay (one step sandwich EIA) for human serum immunoreactive laminin was set up with a pair of monoclonal antibodies prepared against human placental laminin P1 fragment. The assay was characterized by carrying out two immunoreactions simultaneously, laminin P1 fragment reacting with both a monoclonal antibody as a solid phase and a horseradish peroxidaselabeled monoclonal antibody (Fab') against human laminin P1 fragment as conjugate. Sensitivity of the immunoassay was 0.01 ng/well (0.5 μg/l), and linearity was obtained between 0.01-20 ng/well (0.5-1000 μg/l). The levels of laminin in sera from normal individuals and patients with liver cirrhosis, hepatocellular carcinoma and primary biliary cirrhosis were 103 ± 15 μg/l, 228 ± 70 μg/l, 341 ± 163 μg/l and 232 ± 93 μg/l, respectively. Protein immunoblotting showed that the serum immunoreactive laminin measured by the assay was a fragment with rel mol mass of 200 kDa. © 1990.