Antibody coated tubes in T3 - solid phase radioimmunoassay

The aim of this study was to develop a simple and inexpensive form of solid phase radioimmunoassay of T3 (3,5,3'-L- triiodothyronine); for the preparation of solid phase, the adsorption of anti-T3 antibodies to polystyrene tubes has been used. The polystyrene tubes were used without washing or other treatment; each tube was coated by addition of an uniform volume (175 μl) of diluted antiserum of moderately high titer. Antiserum dilution was 1:3000 and the optimal pH of buffer solution was 8.4 - 8.6. The best results were achieved with an exposure time to antiserum of 40 h at 4 deg C. The antibody - coated tubes prepared in this way were verified by using them to the radioimmunoassay of T3. The results obtained with the above mentioned solid phase in T3-RIA of three level control serums were found to be successful for setting up T3- solid phase radioimmunoassay of high precision. (authors)