Independant Certifications

We use the Charles River Endosafe PTS system to test for bacterial endotoxins following USP <85> guidelines:

USP <85> Bacterial Endotoxin Result: <x.xx EU/mL
Because it’s reported as “<x.xx” this indicates the test did not detect endotoxin above the detection limit of the cartridge.

If a result is above the limit of detection of the cartridge, it will be reported as a number (without the “<“).

The following are suitability parameters that verify the system was working properly and the sample prep dilution is appropriate for accurate results. Peptides often interfere with endotoxin detection due to their tendency to bind or mask endotoxins, which can lead to inaccurate low results. To overcome this, samples are typically tested at a large dilution to reduce matrix interference and ensure reliable recovery and detection in compliance with USP <85>.  If the dilution is not correct, the run will fail suitability and we’ll need to adjust the dilution to ensure accurate results. We provide the suitability data to customers for transparency and so they can be confident in the results.

USP <85> Sample CV %:

CV stands for coefficient of variation, a measure of repeatability.

For our lab, CV has to be <25% or the result to be considered valid

USP <85> Spike CV %:

This refers to the precision of the positive control (spiked sample).

Again, for our lab CV has to be <25% or the result to be considered valid

USP <85> Spike Recovery

This tells us how much of the known endotoxin spike was recovered from your sample.

The acceptable range is 50–200% per USP <85>