What is the lal assay and how does it work?

The LAL assay, or Limulus Amebocyte Lysate assay, is a test used to detect endotoxins, which are toxic substances released from the cell walls of gram-negative bacteria. It utilizes lysate derived from the blood cells of the horseshoe crab (Limulus polyphemus), which coagulates in the presence of endotoxins. When a sample is introduced to the lysate, the presence of endotoxins activates a cascade of reactions that leads to gel formation, indicating a positive result. This assay is widely used in pharmaceuticals and medical device industries to ensure product safety.