Endotoxin Detector.pdf

Researchers at the University of Wisconsin-Madison have discovered a potential replacement for horseshoe crab blood in endotoxin testing, using liquid crystal droplets. The current test, known as the limulus amoebocyte lysate (LAL) assay, uses horseshoe crab blood to detect endotoxin, a substance associated with bacterial infections. The new method uses liquid crystals, which respond to endotoxin at concentrations 100,000 times lower than expected, making it highly sensitive and specific.

The liquid crystals have properties of both liquids and solids, and their ordering is influenced by surfaces and contaminants. When exposed to endotoxin, the ordering of the crystals changes, altering their optical properties and making it easy to detect the presence of endotoxin.

The current LAL assay is expensive, with horseshoe crab blood costing thousands of dollars per quart, and is subject to variations due to biological factors. The new test overcomes these issues, but is still in the early stages of development and may take years to become commercially available.

The National Science Foundation (NSF) provided support for the research through the Materials Research Science and Engineering Center (MRSEC) at the University of Wisconsin. The discovery has the potential to lead to the development of high-sensitivity, low-cost sensors for detecting biological substances.