... T4, T3, and rT3 cross-reacted with 3',5'-T2-binding sites on anti-3',5'-T2 antibody only to the extent of ... 0.0025, less than 0.0004, and 0.22%, respectively. 3 ... T4 and 0.24 +/- 0.15 microgram 3',5'-T2/g wet wt. On the basis of these data and those available ... for MCRs of 3',5'-T2 and T4, ...