Direct solid-phase time-resolved immunofluorometric assay of cortisol in serum.
A dissociation-enhanced lanthanide fluoroimmunoassay of serum cortisol based on time-resolved fluorescence is described. The assay is a direct assay, where cortisol immobilized on the wall of a microtiter-strip well competes with cortisol in the sample for the europium-labeled polyclonal antibody. The amount of bound europium-labeled antibody is inversely proportional to the amount of cortisol in the sample. Separation is accomplished by washing the strip well. The assay is carried out in 2 h, at room temperature; it is easy to perform and gives accurate and reliable results. A chaotropic agent, trichloracetic acid, was very effective in releasing cortisol from binding proteins. This finding will have practical importance in the immunoassay field.
D000818:Animals; D000918:Antibody Specificity; D002352:Carrier Proteins; D005455:Fluorescent Antibody Technique; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D007106:Immune Sera; D007700:Kinetics; D007811:Lanthanum; D012016:Reference Values; D012756:Sheep; D013997:Time Factors; D014156:Transcortin / Q000032:analysis; D014238:Trichloroacetic Acid
D002352:Carrier Proteins; D007106:Immune Sera; D014238:Trichloroacetic Acid; D007811:Lanthanum; D014156:Transcortin; D006854:Hydrocortisone