Preparation, purification, and stability of high specific activity 125I-labeled thyronines.
Preparation, purification, and stability of high specific activity 125I-labeled thyronines.
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高比活性 125I 标记甲状腺氨酸的制备、纯化和稳定性。
DOI：
10.1210/endo-102-1-128
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发表时间：
1978
期刊：
影响因子：
4.8
通讯作者：
R. S. Yalow
中科院分区：
文献类型：
--
作者：
Narayana Kochupillai;R. S. Yalow
介绍了一种改进的氯胺-T法，用于通过交换反应或加成反应制备几种放射性碘甲状腺原氨酸，该交换反应得到低比活度的制剂，或者通过加成反应生成比活度高达7mCi/微克的放射性碘甲状腺原氨酸。纸层析法比LH-20层析法更方便，对各种甲状腺原氨酸有更好的拆分能力。外层只有一个碘原子的放射性碘甲状腺原氨酸(3，5，3‘-三碘甲状腺原氨酸和3，3’-二碘甲状腺原氨酸)在有机溶剂中储存几个月都是稳定的。最不稳定的放射性碘甲腺原氨酸是外环上有两个125I原子的化合物(3，3‘，5’-三碘甲腺原氨酸(RT3)由3-碘甲腺原氨酸生成(RT3)，甲状腺激素(T4)由3，5-二碘甲腺原氨酸生成(T4))。RT3和T4在4℃下保存在人血浆中的稳定性比在相同pH下保存在缓冲液中的稳定性要大得多。高比活度[125I]rt3的使用使放射免疫分析的灵敏度达到1pg rt3/ml培养体积。
A modified chloramine-T method is described for the preparation of several radioiodothyronines by an exchange reaction, which results in low specific activity preparations, or by an addition reaction, which yields radioiodothyronines with specific activities up to 7 mCi/microgram. Purification by paper chromatography is shown to be more convenient than by LH-20 chromatography and provides better resolution among the various thyronines. Radioiodothyronines with only a single iodine atom in the outer (3,5,3'-triiodothyronine and 3,3'-diiodothyronine) are stable for several months when stored in organic solvents. The least stable radioiodothyronines are those with two 125I atoms in the outer ring (3,3',5'-triiodothyronine (rT3) produced from 3-iodothyronine and thyroxine (T4) from 3,5-diiodothyronine). The stability of rT3 and T4 stored in human plasma at 4 C is much greater than when stored in buffer at the same pH. The use of high specific activity [125I]rT3 has permitted the development of a radioimmunoassay with a sensitivity of 1 pg rT3/ml incubation volume.