Becker U, Bartl K, Lill H, Wahlefeld A W
Thromb Res. 1985 Dec 15;40(6):721-30. doi: 10.1016/0049-3848(85)90310-x.
We describe a two-step procedure for APTT that can be performed on photometric devices. It includes preincubation of diluted plasma with ellagic acid and phospholipids and a starting reagent that contains calcium and a chromogenic peptide substrate for thrombin, Tos-Gly-Pro-Arg-pNA. Reaction time is recorded from addition of the starting reagent until thrombin formation occurs, and a prefixed amount of substrate is cleaved. The pattern of sensitivity to clotting factors and heparin was similar to clotting assays and the substrate used did not interfere with the activity of factor Xa. An application of the method was made for the Cobas(R) Bio centrifugal analyzer. Absorbance readings were sent to an external computer and were transformed into reaction times by a computer program. Although the results are independent on fibrinogen concentrations, from kinetic data of the reaction curve fibrinogen concentrations can be estimated. Correlation studies showed good correspondence to clotting methods (r = 0.92, n = 53) as well as an excellent precision (CV 3% for inter-assays, n = 15) and high throughput of samples (greater than 100/h) in the automated assay.
我们描述了一种可在光度测定设备上进行的活化部分凝血活酶时间（APTT）两步法。它包括用鞣花酸和磷脂对稀释血浆进行预孵育，以及一种含有钙和凝血酶的显色肽底物Tos-Gly-Pro-Arg-pNA的起始试剂。从加入起始试剂到形成凝血酶记录反应时间，并且一定量的底物被裂解。对凝血因子和肝素的敏感性模式与凝血测定相似，并且所使用的底物不干扰因子Xa的活性。该方法应用于Cobas(R) Bio离心分析仪。吸光度读数被发送到外部计算机，并通过计算机程序转换为反应时间。尽管结果与纤维蛋白原浓度无关，但根据反应曲线的动力学数据可以估算纤维蛋白原浓度。相关性研究表明与凝血方法具有良好的一致性（r = 0.92，n = 53），以及在自动化测定中具有出色的精密度（批间变异系数CV为3%，n = 15）和高样本通量（大于100个/小时）。
