Schroeder H R, Johnson P K, Dean C L, Morris D L, Smith D, Refetoff S
Clin Chem. 1986 May;32(5):826-30.
In this automated apoenzyme reactivation immunoassay system (Ames Optimate) for thyroxin-binding globulin (TBG), the sample and N6-aminohexylflavin adenine dinucleotide-labeled TBG react sequentially with antiserum. Then apoglucose oxidase is added to combine with the free fraction and generate glucose oxidase activity, which is measured colorimetrically. The assay requires 100 microL of sample and covers the clinically significant range for TBG (less than 2.5 to 55 mg/L). The first result is obtained in 16 min; assay of 29 samples and their blanks is completed in less than 1 h. The lower limit of detection is about 2.5 mg/L. Between-assay CVs (n = 9) were less than 9%, within-assay CVs (n = 5) were less than 6%, and analytical recovery of TBG was 103-112%. Reagents are stable at 4 degrees C for at least five months. Results by this method for serum TBG (y) compared well with those determined by radioimmunoassay (x): y = 1.029x--0.352 (r = 0.990, n = 49, Syx = 1.165 mg/L). In addition, with 39 other sera the ratio of total thyroxin (by RIA) to TBG compared well with free thyroxin measured by equilibrium dialysis (r = 0.930) and the free thyroxin index (r = 0.970).
在这种用于甲状腺素结合球蛋白（TBG）的自动脱辅基酶再激活免疫分析系统（Ames Optimate）中，样本和N6-氨基己基黄素腺嘌呤二核苷酸标记的TBG依次与抗血清反应。然后加入脱辅基葡萄糖氧化酶与游离部分结合并产生葡萄糖氧化酶活性，通过比色法进行测量。该分析需要100微升样本，涵盖了TBG临床上有意义的范围（低于2.5至55毫克/升）。16分钟可获得首个结果；29个样本及其空白样本的分析在不到1小时内完成。检测下限约为2.5毫克/升。批间变异系数（n = 9）小于9%，批内变异系数（n = 5）小于6%，TBG的分析回收率为103 - 112%。试剂在4℃至少可稳定保存五个月。用该方法测定血清TBG的结果（y）与放射免疫分析测定的结果（x）比较良好：y = 1.029x - 0.352（r = 0.990，n = 49，Syx = 1.165毫克/升）。此外，对于其他39份血清，总甲状腺素（通过放射免疫分析）与TBG的比值与通过平衡透析测定的游离甲状腺素比较良好（r = 0.930），与游离甲状腺素指数比较也良好（r = 0.970）。
