USP <85> Bacterial Endotoxins Testing
Endotoxin testing built around your product—not just the assay.
PlumGXP provides quantitative kinetic chromogenic testing for routine release, method suitability, validation, water-system programs and investigations—with two complementary platforms, flexible scheduling and operational redundancy.
More Than a Pass / Fail
A program that fits the sample, stage and decision.
Endotoxin testing can be straightforward—until the matrix interferes, the dilution range is limited, a water system trends unexpectedly or a release decision cannot wait. PlumGXP begins with the use case and builds the right testing approach around it.
Two Kinetic Chromogenic Systems
The right platform for the work in front of you.
Both systems quantify endotoxin by monitoring the development of a chromogenic reaction over time. Their formats are different, giving PlumGXP the flexibility to match the assay to sample volume, urgency and study scale.
Focused + rapid testing
Charles River Endosafe® PTS™
The PTS uses single-use cartridges containing preloaded reagents, controls and test channels. After the prepared sample is added, the reader incubates the cartridge, measures the kinetic chromogenic response and calculates endotoxin concentration while evaluating the built-in positive product controls.
- Well suited to focused sample sets and time-sensitive decisions
- Minimal manual assay setup with controls built into each cartridge
- Useful for routine samples, investigations and rapid operational support
- Cartridge sensitivities can be selected to support the required test range
High throughput + complex studies
Sievers Eclipse
The Eclipse uses a centrifugal microfluidic plate. As the plate spins, microchannels and metering chambers distribute samples, water and reagent into optical wells. Preloaded endotoxin standards and positive product controls reduce manual preparation while the system follows the kinetic chromogenic reaction.
- Up to 21 samples on a plate for efficient project execution
- Strong fit for water qualifications, routine programs and larger validations
- Automated liquid distribution helps reduce repetitive pipetting
- Broad analytical range can help when dilution is needed to overcome interference
Operational redundancy matters. Two platforms provide added scheduling flexibility and continuity. Platform selection and any transfer between qualified methods remain product-specific and are managed under an approved testing strategy.
Animal-Free Testing Options
Support for evolving sustainability and sourcing priorities.
When animal-free testing is important to your organization, PlumGXP can evaluate a recombinant reagent option on a compatible platform. Recombinant cascade reagents recreate the endotoxin-responsive enzyme cascade without horseshoe crab-derived lysate.
We work with your Quality Unit to determine the appropriate reagent, platform, suitability work and documentation based on the product, market and intended regulatory use.
Testing Applications
From utility qualification to finished-product release.
PlumGXP supports the matrices and programs where dependable endotoxin control is essential.
Water for Injection
Testing for qualification, verification, routine monitoring, sampling studies, system changes and excursion investigations.
Injectables
Method suitability, validation and routine release testing for parenteral products using an appropriate product-specific dilution strategy.
Biologics & Vaccines
Testing approaches designed around complex matrices, limited dilution windows and the needs of development or GMP programs.
Medical Devices
Support for extracts, rinse or soak preparations, method suitability and quantitative endotoxin evaluation under the applicable requirements.
Materials & Intermediates
Risk-based testing of components, process samples and intermediates to help locate and control endotoxin before final release.
Investigations
Focused retesting plans, matrix-interference assessment, dilution review and data support for excursions or unexpected trends.
Endotoxin Challenge-Set Testing
Evidence that a depyrogenation process performs as intended.
Sterilization controls viable microorganisms. Depyrogenation addresses heat-stable bacterial endotoxin. Endotoxin challenge articles—often vials or other carriers inoculated with a known endotoxin load—are used to challenge a dry-heat depyrogenation process.
PlumGXP can test the challenge set before and after processing, recover the endotoxin from the articles, quantify the recovered level and calculate the log reduction produced by the cycle. This analytical evidence supports qualification or requalification of depyrogenation tunnels, ovens and other validated dry-heat processes.
Who uses this testing—and why?
Sterile drug manufacturers, 503B outsourcing facilities, biologics manufacturers, vaccine operations, CDMOs and component suppliers use challenge sets when qualifying or requalifying a process intended to reduce endotoxin on glass containers or other heat-stable components. Testing can also support major repairs, cycle changes, relocation, adverse trends or investigations into process performance.
Define the study
Confirm challenge article, inoculum, recovery approach, sample groups and acceptance criteria in the approved protocol.
Establish the challenge
Test unprocessed controls to verify the recoverable starting endotoxin load.
Test processed articles
Recover and quantify endotoxin remaining after the defined depyrogenation cycle.
Calculate reduction
Compare pre-process and post-process recovery, evaluate validity and document the demonstrated log reduction.
A Clear Testing Path
Built for routine work—and the samples that are not routine.
Understand
Review the sample, specification, formulation, available volume and intended regulatory use.
Select
Choose the platform, reagent, sensitivity and dilution strategy appropriate to the matrix.
Demonstrate
Establish product-specific suitability by evaluating interference and positive product control recovery.
Execute
Move into controlled routine, validation or investigation testing with clear documentation.
Frequently Asked Questions
Bacterial endotoxin testing, explained.
What is product-specific method suitability?
Method suitability demonstrates that the product matrix does not inhibit or enhance the endotoxin reaction at the selected test dilution. The study evaluates positive product control recovery and helps establish a valid routine method within the maximum valid dilution.
How do you choose between the PTS and Eclipse?
The choice depends on sample count, urgency, matrix behavior, required sensitivity, available sample volume and the intended study. PTS is especially useful for focused or time-sensitive testing; Eclipse is particularly efficient for larger sample sets, water programs and validation studies. PlumGXP recommends the platform after reviewing the project.
Can PlumGXP test with animal-free reagents?
Yes. A recombinant, animal-free reagent option can be evaluated on a compatible platform when requested. Suitability, validation or bridging requirements depend on the product and regulatory strategy and should be agreed with the client Quality Unit.
Can you support WFI system qualification and routine monitoring?
Yes. We can support endotoxin testing during qualification and verification of Water for Injection systems, then continue with routine monitoring, post-maintenance testing, change assessment and excursion investigations.
Is endotoxin challenge testing the same as product release testing?
No. Product testing measures endotoxin in a water, material, device extract or drug-product sample. Challenge-set testing evaluates the performance of a depyrogenation process by comparing recovered endotoxin from unprocessed controls with recovered endotoxin from processed challenge articles.
Does sterilization destroy bacterial endotoxin?
Not necessarily. Many sterilization processes are designed to inactivate microorganisms but do not reliably destroy endotoxin. Where endotoxin reduction is required, a separately validated depyrogenation process and appropriate challenge strategy may be necessary.
Can you help with an endotoxin excursion or unexpected result?
Yes. We can support a controlled investigation plan that considers assay validity, dilution, interference, sampling, water-system trends, materials and process history. Retesting should follow a scientifically justified, pre-approved approach rather than testing into compliance.
Bring us the sample—and the question behind it.
Whether you need a routine release method, a WFI qualification program, animal-free testing or support for a depyrogenation challenge study, PlumGXP will help define a practical path forward.
Let’s Talk About Your Project →Technical framework: USP <85> Bacterial Endotoxins Test; USP <86> Bacterial Endotoxins Test Using Recombinant Reagents; USP <1228.5> Endotoxin Indicators for Depyrogenation; and applicable product-specific requirements. Platform descriptions based on manufacturer information from Charles River and Veolia Sievers.