RIA: the only way to go?
D000818:Animals; D001681:Biological Assay; D002645:Chickens; D006801:Humans; D007553:Isotope Labeling; D008722:Methods; D010281:Parathyroid Hormone / Q000032:analysis*; D011863:Radioimmunoassay / Q000379:methods*; D014316:Tritium
D010281:Parathyroid Hormone; D014316:Tritium