Pep Sterility Fails - Big Deal?

Honestly, these batches are almost never totally sterile. That's why nobody bothers checking, and why everyone argues about using sterile water, BAC water, and filtering.
 
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Some people are dramatic about this stuff. When a lab had a bad test, some people basically told me to off myself just because I said it wasn't a huge deal.
 
Is the lab doing a qualitative or quantitative test? Just curious since they just say 'fail'. Seems like qualitative would be faster.
 
I was wondering about what else is in these things besides the pep itself. Got this info and figured I'd share:

Process-Related Impurities:

These are leftovers from making the stuff, like solvents and reagents.

* Stuff like Trifluoroacetic Acid (TFA) from cleaving the peptide.
* Salts and buffers from purification (HPLC).
* Tiny bits of metals or other elements from the materials or equipment.
* Maybe even a little bit of a different peptide if they make more than one in the same place.
 
If people ever wondered whether resellers are getting their stuff from the same place, here's your answer.

If one seller has Triz that fails a test, bet your bottom dollar other resellers have Triz in the same range that fails too. They're all getting it from the same wholesaler.
 
Yeah, I was surprised to see failures from all kinds of sources. Makes me think I should just switch to pens, and filter it since you're taking it from the vial anyway.
 
Yep. Sterility is about live bugs that will grow in a dish, or inside you. Chemicals are a purity problem. I assume the lab tests for sterility by mixing the sample with sterile water, not BAC. Not sure BAC would even kill bugs anyway - the alcohol is low. It's for stopping future growth, not necessarily killing what's already there.
 
Our bodies are pretty good at fighting things off. It's probably not a big deal, but obviously, I wouldn't buy these batches on purpose. I don't think I've ever used a peptide that had a sterility test. I'm still kicking.
 
Okay, here's some info on those salts and buffers I mentioned earlier:

Common Residual Salts and Buffers

* Trifluoroacetate (TFA Salts) - From Trifluoroacetic Acid used for cleavage. Most peptides are delivered as a TFA salt.
* Acetate (Acetate Salts) - Acetic acid or Ammonium Acetate. Sometimes used to replace TFA.
* Hydrochloride (HCl Salts) - Hydrochloric Acid. Used for pharmaceutical-grade stuff.
* Volatile Buffers - Like Ammonium Bicarbonate, Formic Acid, Triethylamine.
* Non-Volatile Salts - Like Sodium Phosphate, Sodium Chloride, Potassium salts.

These remain because they're used in HPLC purification.
 
Yes and no. "Manufacturers" make the raw pep and "Finishers" freeze dry it. Usually different companies. More finishers than manufacturers. The same raw peptide from one manufacturer could fail at two finishers but pass at the third. Or all three could get bad stuff.
 
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