Even minimal amounts of endotoxin, less than a billionth of a gram, can trigger this immune response. This occurs via a complex clotting cascade, which has been extensively investigated since the LAL assay was first developed. The first enzyme in this cascade is the Factor C enzyme (the biosensor), which binds to the hydrophobic Lipid A component of the LPS molecule to initiate a cascade of enzymatic reactions that result in the formation of a blood clot. LAL testing takes advantage of this endotoxin-sensitive clotting cascade to produce a qualitative assessment of the presence/absence of endotoxin in a sample. Since it was first developed, numerous attempts have been made to improve the sensitivity and efficiency of the LAL assay by changing the formulation of the LAL reagent and the assay methodology.