Vasopressin, RIA, 100 tests
After solid phase extraction (SPE) or ethanol extraction of the plasma samples, vasopressin is assayed by a competitive radioimmunoassay.
Urinary vasopressin can be measured directly. This assay uses a rabbit anti-vasopressin antiserum and a radioiodinated vasopressin [125I] tracer. Bound and free phases are separated by a second antibody bound to solid phase particles, followed by a centrifugation step. The radioactivity in the bound fractions is measured and a typical calibration curve can be generated.
The values of the extracted samples are corrected for extraction recovery.