Some proteins don’t fail because they’re designed badly; they fail because they’re silently contaminated. The culprit has been misleading science for over a century: endotoxins.
In the early 1900s, doctors faced a strange phenomenon. Patients injected with otherwise safe drugs developed sudden fevers, a condition so common it was nicknamed “water fever.”
The culprit wasn’t the drugs themselves, but bacterial fragments called endotoxins. These molecules are incredibly resilient. They remain even after bacteria die, and they activate our immune system through a receptor known as TLR-4, discovered in 1998 by Nobel laureate Bruce Beutler.
This discovery explained why even trace amounts of endotoxin trigger an outsized immune response. But it also revealed a problem that continues to challenge biotech today: endotoxins don’t just harm patients — they mislead science.
- They stick tightly to proteins, especially hydrophobic or membrane proteins.
- They contaminate reusable purification equipment, spreading across labs and facilities.
- They disrupt protein folding and function, clouding both experimental results and manufacturing runs.
For small-molecule drugs, these challenges are manageable. For biologics (antibodies, vaccines, and other protein therapeutics) endotoxins are one of the hardest problems in the industry. The global detection market alone is valued at more than $2 billion.
At Sino Biological, we have a dedicated production line designed around to tackle this problem from the source. All the way from the choice of materials to clean-in-place protocols. Our new line of products, Propure, achieves endotoxin levels up to 0.01 EU/mg, 100 times lower than industry standards.
Visit https://www.sinobiological.com/news/propure-endotoxin-free-proteins for more information.