Related Experiment Video
Updated: Jul 22, 2026
Air-sampled Filter Analysis for Endotoxins and DNA Content
Published on: March 7, 2016
Comparison of bacterial endotoxin testing methods in purified pharmaceutical water matrices
Marine Marius1, Frédéric Vacher1, Thierry Bonnevay1
1Analytical Sciences, Sanofi Pasteur, Marcy l'Etoile, 1541 Avenue Marcel Mérieux, 69280, France.
Abstract:
Current bacterial endotoxin testing systems can be labor-intensive and time-consuming, involving several manual pipetting steps. In our quality control laboratory, annually, we test about 15,000 samples of different grades of purified water, WFI and water samples taken to validate cleaning procedures for endotoxins. We are currently using the Kinetic-QCL™ assay which is a pharmacopeia method that provides reliable results. We compared this assay with another Limulus amebocyte lysate (LAL)-based assay (Endosafe®-MCS) and an alternative endpoint fluorescent recombinant Factor C (rFC) assay (ENDOZYME II GO®). Both these assays have been developed to reduce analyst preparation time. Our objective was to assess if they could increase the throughput of our testing while maintaining low rates of invalid results. The results demonstrated that the two most appropriate methods for rapid endotoxin detection in water are our current assay, K-QCL, and the rFC-based assay, ENDOZYME II GO. This latter assay was found to be less sensitive to interference than our current assay, particularly in cleaning validation water samples. It also showed better performance, accuracy, repeatability and had a shorter time-to-results. ENDOZYME II GO assay allows quick testing of large numbers of samples with reliable results and is a good alternative for conventional LAL assays.
Insights
The recombinant Factor C (rFC) assay ENDOZYME II GO offers a faster, more accurate alternative to traditional bacterial endotoxin testing. It provides reliable results for purified water and cleaning validation, increasing testing throughput.
Area of Science:
- Microbiology
- Analytical Chemistry
- Pharmaceutical Quality Control
Background:
- Current bacterial endotoxin testing methods are often manual, time-consuming, and labor-intensive.
- Annual testing of approximately 15,000 samples of purified water, WFI, and cleaning validation samples necessitates efficient methodologies.
- The Kinetic-QCL™ assay is a standard pharmacopeia method for reliable endotoxin detection.
Purpose of the Study:
- To evaluate alternative endotoxin detection assays for increased throughput and reduced analyst preparation time.
- To assess the performance, accuracy, and reliability of new assays compared to the current standard.
- To determine if alternative assays maintain low rates of invalid results in a high-volume quality control setting.
Main Methods:
- Comparative analysis of three endotoxin detection assays: Kinetic-QCL™ (K-QCL), Endosafe®-MCS (LAL-based), and ENDOZYME II GO® (rFC-based).
- Evaluation of assays for speed, accuracy, repeatability, sensitivity to interference, and time-to-results.
- Testing conducted on purified water, WFI, and cleaning validation water samples.
Main Results:
- The ENDOZYME II GO assay demonstrated superior performance, accuracy, and repeatability compared to the K-QCL assay.
- The rFC-based assay showed reduced sensitivity to interference, especially in cleaning validation samples.
- ENDOZYME II GO offered a significantly shorter time-to-results, enabling quicker high-volume sample testing.
Conclusions:
- The ENDOZYME II GO assay is a suitable and efficient alternative to conventional Limulus amebocyte lysate (LAL) assays for bacterial endotoxin detection.
- This rFC-based assay enhances testing throughput and reliability for purified water and cleaning validation in quality control laboratories.
- The ENDOZYME II GO assay provides a valuable option for rapid, accurate endotoxin testing, minimizing manual steps and improving laboratory efficiency.
