Endotoxin testing methods — what worked for you?

Dr.SleepRoch said:

Inter-laboratory variation comes from real methodological differences, not sloppiness: which reference standard was used and how it was itself…

Bookmarking. The distinction being drawn above is the one nobody else makes. Taking it to my next appointment.

From the other side of the consultation, briefly.

COA red flags for certificates of analysis — here's what to look for when reviewing a Certificate of Analysis:

• No HPLC data: If there's no chromatography graph, it's not a real COA
• Exact 100% purity: Suspicious — real testing always shows slight variation
• No batch number: Can't trace back to specific production
• No endotoxin testing: For injectables, this is essential
• Template looks like it was made in Word: Professional labs have standardized formats

I have seen fake COAs that are literally photoshopped. Always verify independently if possible.

Dr.RenalNash said:

Community-verified vendors for certificates of analysis: I maintain a spreadsheet of Janoshik-verified test results submitted by community members.

Vendor quality matters when discussing certificates of analysis. I've tested my last 5 batches through Janoshik and purity has ranged from 97.0% to 99.2%. Consistency is key.

For anyone new: always request the COA, and consider independent verification. The $300 for a Janoshik test is worth the peace of mind.

mona_PHX said:

They are not contradictory, they measure different things, and this is the single most common misreading of a certificate.

I tested my certificates of analysis batch through Janoshik — 98.7% purity. That's within acceptable range for compounded peptides. Turnaround was 10 business days.

The test costs ~$142 but gives you actual HPLC chromatography data plus mass spec confirmation. For the peace of mind alone, it's worth every penny. I test every new batch from a new vendor.

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