Use of chromatography tubes in triiodothyronine and thyroxine RIA

Simple, convenient radioimmunoassays for total triiodothyronine and total thyroxine in human serum are discribed. Ascending dry column chromatography is used to separate the free and antibody-bound hormone. The method allows for separation by absorption, without centrifugation. The use of test tubes containing pre-measured quantities of lyophilized radioactive reagent obviates unnecessary handling of radioactive solutions.