PTH Intact, IRMA, 96 tests
DiaSource hPTH-120 min-IRMA is a two-step immunoradiometric assay based on coated-tube separation. It allows the determination of intact human PTH (hPTH) in serum.
Goat antibodies specific to the 1-34 hPTH fragment (N-terminal fragment) are attached to the lower and inner surface of the plastic tubes. Calibrators or samples are added to the tubes.
After 1 hour incubation, washing removes the occasional excess of antigen, mid-regional and C-terminal fragments. 125I labelled monoclonal antibodies specific to the 44-68 hPTH fragment are added. After 1 hour incubation and washing the remaining radioactivity bound to the tube reflects the intact h-PTH concentration.
This two-step IRMA is highly specific of the intact h-PTH and does not cross react with active and inactive fragments even at high concentrations as suggested by HACKENG and al.