血清游离甲状腺素(FT4)双抗固相放射免疫分析方法的建立

利用双抗固化试管建立了检测血清中游离甲状腺素（ＦＴ４）的固相放射免疫分析方法。游离ＦＴ４和１２５Ｉ标记的ＦＴ４类似物竞争与包被管上的固化抗体结合。检测可以在２ｈ内完成。检测范围为０．１２－７５ｐｍｏｌ／Ｌ。批内、批间平均变异系数分别为１．７％－４．４％和３．２％－９．１％。非特异性结合小于１％。该分析与商品ＦＴ４标记抗体ＲＩＡ分析药盒比较，线性回归斜率为１．０８，截距２．３，相关系数为０．８５。该方法操作简便、重复性好，多项分析指标优于常规的放免分析方法，为一种简便、精密和准确的分析方法。

Establishment of a double-antibody solid-phase radioimmunoassay for free thyroxine in serum

Using double-antibody coated tubes, a solid-phase radioimmunoassay for free thyroxine (FT4) in serum has been developed. The antibody immobilized onto the surface of the coated plastic tubes competed for binding with FT4 or 125I labelled T4-analogue. Whole test was completed within 2h. The detectable range was 0.12 to 75pmol/L FT4 in serum. The mean coefficients of variation within and between assays were 1.7%-4.4% and 3.2%-9.1%, respectively. The non-specific binding was less than 1%. This new assay was compared with a commercial radioimmunoassay kit for FT4 (labelled antibody). A linear regression analysis yielded a slop of 1.08, an intercept of 2.3 and a correlation coefficient of 0.85. Most of the analytical indices are better than the routine RIA procedure. Therefore it appears to be a simple, precise and accurate new assay method.