title: Enzyme-linked immunoassay for placental lactogen in human serum.
abstract: We describe an enzyme-linked immunoassay for measuring human placental lactogen (HPL) in serum. After suitable dilution, sera are pipetted into the wells of polyvinyl microtitre plates previously coated with anti-HPL. After incubation the sera are decanted, and replaced by a conjugate of horseradish peroxidase and anti-HPL. An amount of enzyme proportional to the concentration of HPL in the serum is bound to the wells via an antibody--HPL--antibody bridge. Peroxidase activity is measured by oxidation of o-phenylenediamine, the resulting color being related to the concentration of HPL. Results correlate well with those by radioimmunoassay (r = 0.96). Our between-assay coefficient of variation was 13%; no discernible effect of protein was observed. This 4-h assay can be used to monitor placental function in pregnancy.
mesh_terms: D005069:Evaluation Studies as Topic; D005260:Female; D006735:Horseradish Peroxidase; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007124:Immunoenzyme Techniques; D010928:Placental Lactogen / Q000097:blood*; D011247:Pregnancy; D011296:Prenatal Diagnosis
chemical_list: D010928:Placental Lactogen; D006735:Horseradish Peroxidase