Development and validation of an immunoradiometric assay of parathyrin-related protein in unextracted plasma

This two-site immunoradiometric assay for human parathyrin-related protein 1-86 (PTHRP1-86) in plasma uses a mouse monoclonal antibody to PTHRP1-34 coupled to cellulose particles for immunoextraction of N-terminal immunoreactivity, and a rabbit antiserum to PTHRP37-67 that is indirectly labeled with 125I-labeled PTHRP37-67 for quantifying the bound analyte. The detection limit of the assay is 0.23 pmol/L, corresponding to 0.4 pg (0.04 fmol) per...