改良缺血修饰白蛋白测定方法（白蛋白-钴结合试验）的建立

目的建立改良的缺血修饰白蛋白（IMA）测定方法[白蛋白-钴结合（ACB）试验]。方法以1-亚硝基-2-萘酚（NN）代替二硫苏糖醇（DTT）作为显色剂,确定试验的基本条件（最佳波长、反应时间、试剂稳定性等）,并对该试验的精密度、敏感性、线性等进行评价。测定急性心肌梗死（AMI）和胸痛患者的IMA值并进行统计学分析。结果改良ACB试验最佳吸收波长为410 nm,反应体系0～25 min时吸光度值变化稳定,试剂在室温和4℃30 d内性能稳定,反应体系线性良好。批内变异系数（CV）为2.67%,批间CV为5.44%。应用显色剂NN对钴离子（Co2＋）的最低检出限为0.488 mg/L,应用DTT为7.812 mg/L。三酰甘油（TG）〈2.02 mmol/L、血红蛋白（Hb）〈6.9 g/L、总胆红素（TBil）〈66.0μmol/L时无干扰。AMI组为（1.195±0.320）吸光度单位（ABSU）,胸痛组为（0.855±0.068）ABSU,二者差异有统计学意义（P〈0.01）。结论以NN作为显色剂测定IMA的ACB试验灵敏、方便、简单,适合批量测定。

Establishment of improved albumin cobalt binding assay to detect ischemia modified albumin

Objective To establish an improved albumin cobalt binding（ACB） assay for detecting ischemia modified albumin（IMA）.Methods 1-nitroso-2-naphthol（NN） as a new chromogenic reagent was used to replace dithiothreitol（DTT）,and the basic conditions of the assay were ascertained,including the best absorption wavelength,the best reaction time and the stability of reagent and so on.The precision,sensitivity and linearity of the ACB assay were evaluated.The IMA values of acute myocardial infarction（AMI） group and chest pain group were measured and analyzed statistically.Results The improved method′s best absorption wavelength was 410 nm;its value of absorption changed stably in 0-25 min;the reagent was stable both in room temperature and 4 ℃ within 30 d;the linearity of the method was excellent.The coefficient of variation（CV） of within-run assay was 2.67%,and the CV of between-run assay was 5.44%.The detection limit was 0.488 mg/L when using NN,while it was 7.812 mg/L when using DTT.There was no interference at triglyceride（TG）2.02 mmol/L,hemoglobin（Hb） 6.9 g/L,total bilirubin（TBil） 66.0 μmol/L.The concentration of IMA in AMI group [（1.195±0.320）absorbance units（ABSU）] was obviously higher than that in chest pain group[（0.855±0.068）ABSU]（P 0.01）.Conclusions ACB method in which NN is used as a new chromogenic reagent to detect IMA is sensitive,simple,convenient and suitable for batch detection.