Cederblad G, Harper P, Lindgren K
Clin Chem. 1986 Feb;32(2):342-6.
A spectrophotometric method for carnitine has been adapted to the Cobas Bio centrifugal analyzer. The addition of carnitine to a system containing carnitine acetyltransferase (EC 2.3.1.7) and acetyl-CoA gives rise to the formation of CoA. The system is coupled to 5,5'-dithiobis(2-nitrobenzoate) (DTNB). Assay response varied linearly with concentration of carnitine over a wide concentration range. The total CV was 5.5% for a carnitine concentration in serum of 58.0 mumol/L. Analytical recovery of carnitine added to a serum sample was 93%. No interference was found in icteric, not grossly hemolyzed, lipemic, or uremic sera. Comparison with a radioenzymatic method showed that results correlated well (r greater than 0.965) but the present method gave values proportionally greater by 10 to 25% for samples of plasma, dialysis fluid, urine, and muscle tissue. Advantages over the original spectrophotometric assays involving DTNB include low reagent costs, rapidity, simplicity, and reproducibility. However, this modification is not as sensitive and probably not as specific as the radioenzymatic methods.
一种用于测定肉碱的分光光度法已应用于Cobas Bio离心分析仪。在含有肉碱乙酰转移酶（EC 2.3.1.7）和乙酰辅酶A的体系中加入肉碱会生成辅酶A。该体系与5,5'-二硫代双（2-硝基苯甲酸）（DTNB）偶联。在很宽的浓度范围内，测定响应与肉碱浓度呈线性变化。血清中肉碱浓度为58.0μmol/L时，总变异系数为5.5%。添加到血清样本中的肉碱分析回收率为93%。在黄疸、无严重溶血、脂血或尿毒症血清中未发现干扰。与放射酶法比较表明，结果相关性良好（r大于0.965），但对于血浆、透析液、尿液和肌肉组织样本，本方法所得值按比例高出10%至25%。与涉及DTNB的原始分光光度法相比，优点包括试剂成本低、快速、简便和可重复性。然而，这种改进不如放射酶法灵敏，可能也不如其特异。
