固相亲合素在游离甲状腺素免疫检测中的应用

目的：以亲合素－生物素分离技术为基础，尝试通过固化抗原（标记抗体）或固化抗体（标记抗原衍生物）两种免疫分析构型实现具有代表性的游离激素－游离甲状腺素（FT4）的固相免疫分析测定。方法：应用牛血清白蛋白－亲合素联接物制备固相亲合素，以此为基础制备固相生物素化甲状腺素衍生物或固相生物素化抗甲状腺素抗体，并分别用于标记抗体法或标记抗原衍生物法的FT4免疫分析。结果：标准曲线的四参数非线性拟合度良好；标记抗标法测定的灵敏度为0.42pmol/L，批内批间的CV％均小于7％，标记衍生物法的灵敏度为0.36pmol/L，批内批间的CV％均小于7％，两种方法相关性良好（r=0．9734，P＜0．01）。结论：通过应用固相亲合素固化抗原或固化抗体两种方式，进一步肯定了固相亲合素作为通用固相分离技术在免疫分析中的应用价值，为游离甲状腺素测定提供了实验 依据。

Experimental research on immunoassay based on solid-phase avidin for free thyroxine

Objective To fry to develop two methods of solid phase immunoassay for free thyroxine by using an avidin biotin separation technique.Which characterized separately by labeling antibody or analog of antigen.Methods Solid phase avidin was prepared with conjugates formed by avidin and bovine serum albumin.The biotinylated thyroxine derivative or biotinylated anti T 4 were then bound to solid phase avidin to form solid phase antigen or solid phase antibody which was used for FT 4 immunoassay.Results The standard curves were fitted very well by non linear curve fitting with 4 parameters.The sensitivity was 0.42 pmol/L for labeling antibody and 0.36 pmol/L for labeling analog of autigen,respectivity,and both of the methods had good precision.The coefficients( CV ) were less than 7% in both intra assays and inter assays.Comparison between the two methods also showed good correlatior( r =0.9734, P <0 01).Conclusion The experimental results showed that solid phase avidin is apt for the immobilization of both antibody and antigen.This result may be helpful for the automation of free hormone determination.