Endotoxin Detection Assays & Services

Better For Your Lab.
Better For The Planet.

ENDONEXT™ endotoxin detection assays from bioMérieux are ushering in a new era of smarter, more sustainable pharmaceutical quality control.

Based on Recombinant Horseshoe Crab Factor C (rFC), ENDONEXT technology not only eliminates the need to harvest horseshoe crab blood—it makes your entire lab more efficient. With 100% endotoxin specificity, lot-to-lot consistency, and more streamlined workflows, ENDONEXT provides reliable results everywhere from in-process controls to final product testing on the most challenging matrices.

One of our main missions is to innovate in the field of endotoxin detection, with a strong focus on patient safety. Our ENDONEXT™ Endotoxin Detection Assays are based on recombinant Horseshoe Crab Factor C (rFC) to give you the performance and security of supply for even the most challenging quality control needs throughout your manufacturing process. Using synthetic rFC instead of blood cells from Horseshoe crabs not only ensures ecological sustainability, but also unprecedented accuracy, sensitivity, lot-to-lot consistency, and easy automation.

ENDONEXT at a glance:

  • Sustainable rFC without using horseshoe crabs
  • 100% endotoxin specificity—no more false positives from β-Glucan
  • Recombinant production provides high lot-to-lot consistency
  • Fluorescence end-point assays in 96-well microplate format
  • Validated according to standard pharmacopoeial Bacterial Endotoxin Testing criteria

With our ENDOXPERTS™ Endotoxin Services we also provide routine testing and feasibility studies as well as specialized services for analytical issues such as Low Endotoxin Recovery (LER). Our work for leading pharmaceutical companies has resulted in validated methods for LER, fulfilling regulatory requirements. Applying true scientific soundness, we continue our contribution to the deepened knowledge of the LER phenomenon and complex nature of endotoxin.

ENDONEXT™ Endotoxin Detection Kits


The enhanced second generation of ENDOZYME is a flexible and easy-to-use endotoxin detection assay.

  • State-of-the-art sensitivity down to 0.001 EU/mL
  • Flexible assay time from 15-120 minutes depending on required sensitivity
  • Particularly suited for formulation, research, and final product testing


The rapid Go version of ENDOZYME II featuring GOPLATE™—a microplate pre-filled with required standard curve and positive product control concentrations. 

  • Ready-to-use GOPLATE™ eliminates manual preparation of standard dilutions and PPCs
  • Over 50% reduction in handling time compared to conventional microplate assays
  • Significantly reduces risk of human error during preparation stages
  • Ideal for in-process control of water and raw materials as well as product release testing

>50% reduction of handling time

 Minimized human error rate

 Down to 15 min assay time for   in-process control of water


With its unique built-in sample preparation step, the ENDOLISA assay revolutionizes endotoxin testing of complex samples. 

  • ELISA-like format features 96-well plate pre-coated with a specific endotoxin-binding phage protein
  • Overcomes limits of traditional methods such as inhibition and enhancement
  • Unprecedented tolerance of organic solvents, detergents, and chaotropic agents
  • Low to no dilution of samples

For complete matrices

Highly robust method

The ENDONEXT endotoxin testing range offers a solution for each application
•Fast workflow 
•Flexible format
•Complex samples
In-process control of water & raw materials +  
Formulation & research + +
Final Product + +
Sample interfering/invalid with LAL     +
Low endotoxin recovery* +

✔ Suitable     ✔+ Highly Suitable   
*When combined with dedicated sample preparation applying the ENDO-RS method by bioMérieux

Low Endotoxin Recovery (LER)

ENDO-RS enables full quantitative recovery of endotoxin in biopharmaceutical samples affected by Low Endotoxin Recovery (LER) independent of storage time and endotoxin concentration.

In several scientific studies it has been demonstrated that biologics typically containing protein in high concentrations and non-ionic surfactants such as polysorbate in combination with chelating agents are likely to change the aggregate state of the analyte endotoxin in such a way that it is no longer accessible for detection with Factor C-based endotoxin tests such as Limulus Amebocyte Lysate (LAL) and Recombinant Factor C (rFC).

Selected scientific publications on LER and the biological activity of masked endotoxin:

  • Masking of endotoxin in surfactant samples: Effects on Limulus-based detection systems - Reich et al, Biologicals, 2016
  • Biological Activity of Masked Endotoxin - Schwarz et al, Nature, 2017
  • Low Endotoxin Recovery, A Brief Overview - Wintzingerode (Roche), American Pharmaceutical Review, 2016

The ENDO-RS method developed by bioMérieux is a unique toolbox for sample preparation addressing masking of endotoxin at the root cause. The method enables complete endotoxin recovery in biopharmaceutical drug formulations affected by Low Endotoxin Recovery (LER). All needed reagents are included in the kit for developing a formulation-specific sample preparation protocol in combination with the ENDOLISA® assay. It is possible to apply ENDO-RS in combination with conventional LAL, but not directly without interface optimization.

Contact our ENDOXPERTS™ Services to find out how we develop a protocol according to regulatory requirements.




Endotoxin Recovery Kit (Surfactant)

A tool box for demasking endotoxin in pharmaceutical formulations exhibiting Low Endotoxin Recovery (LER)

ENDOXPERTS Endotoxin Services

Comprehensible Endotoxin Services with a special expertise in Low Endotoxin Recovery (LER) including hold-time studies, test protocol development and validation.

Feasibility Studies:

We offer feasibility and comparison studies using rFC and conventional methods.

Method Validation:

Our method validation services include all of the validation steps required during a product validation and requested by regulatory authorities.

Endotoxin Hold-Time Studies:

In order to verify the reliability of the used endotoxin assay, we conduct and report time-dependent endotoxin spiking studies with undiluted drug product lots according to regulatory requirements. The drug product lots are spiked with specified endotoxin levels and held for several days, depending on sample, before being assayed. A decline in endotoxin concentration over time is indicative of LER.

Root-cause analysis of LER:

In case of a drug product being affected by LER, a thorough investigation of the underlying causes of the phenomenon in the specific drug product is conducted, as well as for sample containers, API formulation and individual excipients.

Demasking Protocol Development:

We are specialized in developing and validating custom demasking protocols. The new methods ENDO-RS® and EndoLISA® combined provide the technological basis for accurate determination of endotoxins in biopharmaceuticals containing surfactants (e.g. polysorbate). The ENDO-RS® sample preparation can also be applied in combination with conventional BET test methods, such as LAL, which requires an optimization of the interface. As biopharmaceutical formulations differ in concentrations and compositions, for each formulation an optimized protocol is needed. Our demasking service includes method transfer, validation, training and support.

ENDONEXT™ Accessory Products

Accessory products free from detectable levels of endotoxin.

Coming soon: Software and instrumentation.


ENDOGRADE® Glass Test Tubes

Endotoxin-free borosilicate glass test tubes with aluminum screw cap.

Ideal vessels for samples and the dilution of endotoxin standards contained in the ENDOZYME® II and ENDOLISA® kits. Manufactured according to a dry heat depyrogenation procedure.





Ultra-pure water for reconstitution and dilution of test samples and reagents.

Certified to contain less than 0.001 EU/mL and ideal for preparing solutions and reagents for bacterial endotoxin testing.

Pioneering Diagnostics