Bioendo EC Endotoxin Test Kit (End-point Chromogenic Assay, Diazo Coupling) provides a fast measurement for endotoxin quantification. The endotoxin in the sample activates a cascade of enzymes in Amebocyte Lysate, the activated enzyme splits the synthetic substrate, releasing a yellow-colored item. Then the yellow item can further react with diazo reagents to form purple items with maximum absorbance at 545nm. A regular spectrophotometer or plate reader is required to read the absorbance at 545nm.