What Is Endotoxin?
Category: Quality
A toxic substance released from bacterial cell walls. Endotoxin contamination in peptide products can cause fever, inflammation, and serious adverse reactions. Quality testing should check for endotoxin levels.
Detailed Explanation
Endotoxins are lipopolysaccharide (LPS) components of the outer cell wall of gram-negative bacteria. They are extremely potent immune stimulators and can cause fever, inflammation, hypotension, and in severe cases, septic shock. In peptide manufacturing, endotoxin contamination can occur during synthesis, handling, or storage. Even peptides with high chemical purity can contain dangerous levels of endotoxins if proper manufacturing controls are not in place.
Practical Context
When evaluating peptide quality, endotoxin testing is as important as purity testing. A Certificate of Analysis should include endotoxin levels, ideally measured using the LAL (Limulus Amebocyte Lysate) test. Safe levels are generally considered to be below 0.25 EU/mL for injectable products. If a vendor cannot provide endotoxin testing results, consider this a significant red flag about their quality control standards.
Frequently Asked Questions
How are endotoxins tested?
The most common test is the LAL (Limulus Amebocyte Lysate) test, which uses an extract from horseshoe crab blood cells that reacts with endotoxins. Results are reported in Endotoxin Units (EU).
Related Terms
- Certificate of Analysis (COA) - A document from a testing laboratory confirming the purity, identity, and quality of a peptide product. Reputable vendors provide COAs for each batch, ideally from third-party labs.
- HPLC (High-Performance Liquid Chromatography) - The gold standard analytical method for measuring peptide purity. Separates components of a sample to determine what percentage is the desired peptide vs. impurities. Look for 98%+ purity.
- Mass Spectrometry (MS) - An analytical technique that identifies compounds by their molecular weight. Used alongside HPLC to confirm that a peptide is actually what the label claims.