Gleeson M, Maughan R J
Clin Chim Acta. 1987 Jul 15;166(2-3):163-9. doi: 10.1016/0009-8981(87)90418-9.
Existing methods for the estimation of the branched-chain amino acids (BCAA) normally require sophisticated, expensive instrumentation. An alternative is an enzymatic spectrophotometric method but this requires relatively large volumes of blood and is rather time-consuming. A simple enzymatic fluorimetric method for the measurement of the BCAA in microliter samples of plasma is described here. The method is based on the oxidative deamination of L-leucine, L-isoleucine and L-valine by leucine dehydrogenase from Bacillus species. The NADH which is formed in stoichiometric quantities is estimated fluorimetrically. In the presence of the ketone-trapping agent hydrazine the reaction goes to completion in an alkaline incubation medium at 37 degrees C. By this method the combined BCAA can be measured routinely in 20 microliter sample of plasma. The test exhibits acceptable precision and reproducibility.
现有的支链氨基酸（BCAA）估算方法通常需要精密、昂贵的仪器设备。另一种方法是酶促分光光度法，但这需要相对大量的血液，且相当耗时。本文介绍了一种用于测量微升血浆样本中BCAA的简单酶促荧光法。该方法基于芽孢杆菌属的亮氨酸脱氢酶对L-亮氨酸、L-异亮氨酸和L-缬氨酸的氧化脱氨作用。通过荧光法估算化学计量生成的NADH。在酮捕获剂肼存在的情况下，反应在37摄氏度的碱性孵育介质中进行完全。通过这种方法，可以常规测量20微升血浆样本中的总BCAA。该检测具有可接受的精密度和重现性。
