Use of cholesterol oxidase for assay of total and free cholesterol in serum by continuous-flow analysis.
Use of cholesterol oxidase for assay of total and free cholesterol in serum by continuous-flow analysis.
复制标题
使用胆固醇氧化酶通过连续流分析测定血清中的总胆固醇和游离胆固醇。
作者：
W. Richmond
本文介绍一种血清总胆固醇的测定方法，用美国TECHICON公司的AutoAnalyzer II(TECHICON)自动分析仪，用碱皂化胆固醇酯，用表面活性剂(Triton X-100)把胆固醇放在胶束水溶液中，用胆固醇氧化酶氧化胆固醇，用Ti4+和二甲酚橙络合测定过氧化氢。还描述了一种基于相似原理的血清中游离胆固醇的测定方法，这两种方法可以在双道自动分析仪II上同时运行。胆固醇在异丙醇中的标准溶液比血清具有更差的携带特性，因此不能达到与同等浓度的血清相同的连续流动稳定状态。通过使用含有白蛋白的胆固醇胶束溶液进行标准化，避免了由此产生的潜在校准误差。证明了胆固醇在异丙醇溶液中的过氧化胆固醇的形成，这构成了酶胆固醇测定中的另一个潜在的误差来源。在分析患者血清时，总胆固醇测定的结果与使用胆固醇酯酶和胆固醇氧化酶的机械化方法的结果有很好的相关性；自动Abell方法的结果与胆固醇在异丙醇中的溶液进行了校准，结果略高。通过我们的自动胆固醇脱氢酶分析测定游离胆固醇与总胆固醇的比率，给出的值与使用洋地黄素沉淀的公开结果很好地吻合。
Idescribe an assay for total cholesterol in serum, with use of the AutoAnalyzer ii (Technicon), in which cholesterol esters are saponified by alkali, cholesterol is held in aqueous micellar solution with a surfactant (Triton X-100) and oxidized by cholesterol oxidase, and the hydrogen peroxide produced is measured by chelation with Ti4+ and xylenol orange. An assay for free cholesterol in serum, based on similar principles, is also described, and the two can be run simultaneously on a dual-channel AutoAnalyzer II. Standard solutions of cholesterol in isopropanol have poorer carryover characteristics than sera, and therefore do not reach the same continuous-flow steady state as sera of equivalent concentrations. Consequent potential calibration errors are avoided by using micellar solutions of cholesterol containing albumin for standardization. The formation of cholesterol peroxide in solutions of cholesterol in isopropanol is demonstrated, and this constitutes another potential source of error in the calibration of enzymic cholesterol assays. In analyzing patients' sera, results of the total cholesterol assay correlate well with those of a mechanized method in which cholesterol esterase and cholesterol oxidase are used; an automated Abell method, calibrated with solutions of cholesterol in isopropanol, gave slightly higher values. Determinations of the ratio of free cholesterol to total cholesterol by our automated cholesterol exidase assays given values that agree well with published results in which digitonin precipitation is used.