Abstract
The importance of endotoxin measurement in safety management of dialysis fluid is widely recognized and many hemodialysis facilities are evaluating the purity of dialysis fluid by endotoxin testing. As endotoxin testing using Limulus reagent is known to be influenced by differences in equipment, instrumentation, and environment in the test laboratory, the Bacterial Endotoxins Test chapter in the Japanese pharmacopoeia specifies that a concurrent endotoxin standard series should be included with each test. To simplify testing, standard curve information provided by the reagent's manufacturer is also often utilized to create an archived standard curve consisting of stored standard line parameters. However, there has been little study on the effectiveness of the archived standard curve in terms of accuracy and precision. In this study, recovery of added endotoxin, detection limit in distilled water, quantitation limit in dialysis fluid, and intermediate precision were evaluated for the use of archived standard curve to measure endotoxin in dialysis fluid according to the draft guidelines for validation of the endotoxin test in dialysis fluid prepared by a study group in the Japanese Society for Hemodiafiltration. The results demonstrate the effectiveness of archived standard curves in endotoxin measurement in dialysis fluid when used under properly controlled conditions of the measurer and instrumentation.
