USP <85> endotoxin testing
Endotoxin causes fever in an injection even when nothing in it is alive. We test it by kinetic chromogenic LAL on three Charles River Endosafe nexgen-PTS readers, and every sample carries the positive product control that proves the number is valid.
How the test is run
The sample is reconstituted and diluted within its maximum valid dilution, then loaded on a single-use Endosafe cartridge that carries its own standard curve, calibrated by Charles River before it ships. Limulus amebocyte lysate reacts with endotoxin and the reader times the colour change; faster onset means more endotoxin. Each sample is run as-is and spiked with a known quantity of endotoxin. If spike recovery falls outside 50 to 200 percent the sample is interfering and the result is not reported until the interference is resolved. The endotoxin limit is calculated from the intended dose as K/M per USP <85> and printed beside the result.
What it costs and what to send
| Price | $199 per sample |
|---|---|
| Turnaround | Within the standard 5–7 business days |
| Sample | One extra sealed vial from the same lot; sterility shares it |
| Reported as | EU/mL or EU/mg, the calculated limit, PPC recovery, cartridge lot and MVD |
| Matrices | Injectable peptides, sterile raw materials, water for injection, devices |
Why the positive product control matters
A certificate that reports an endotoxin number with no spike recovery has skipped the control that USP <85> requires. Peptides, buffers and excipients routinely inhibit or enhance the LAL reaction; without the control a clean-looking result can be an inhibited one. Our certificate prints the recovery next to the result. The background is in Why endotoxin is tested by kinetic chromogenic LAL.
Order it with sterility
Endotoxin and USP <71> sterility together are the release set for an injectable and share one vial. Both are in the 7x testing level in the intake builder, or select them individually; nothing is bundled.
Questions
Can I order endotoxin without identity and purity?
Yes. Select only endotoxin in the intake builder and send one sealed vial.
What limit do you test against?
The limit is calculated from the maximum dose you state at intake using K/M per USP <85>, with K = 5 EU/kg/h for parenterals. If you give no dose we report the measured value against a default stated on the certificate.
Do you offer recombinant factor C?
Not at present. Results are by LAL, which remains the compendial reagent in USP <85>.
Is one vial enough for endotoxin and sterility?
Yes. One sealed vial from the same lot covers both when ordered together.
What if my sample interferes with the assay?
We dilute within the maximum valid dilution and repeat the positive product control. If interference cannot be resolved within the MVD the certificate says so rather than reporting an invalid number.
Related
Peptides testing · USP <71> sterility testing · Why endotoxin is tested by kinetic chromogenic LAL · Peptides testing · SARMs testing · Kratom testing · Hemp testing
Submit a sample
An invoice is issued at submission and the prepaid label is emailed when payment lands.