Chromogenic TAL( the reagents extracted from Chinese horseshoe crab,.  Both LAL and TAL have the same function for endotoxin detection. ) endpoint assay is a quantitative TAL assay formulated with a synthetic substrate which gives a yellow color when acted upon by endotoxin activated enzyme. After the reaction stopped by acid, the OD value of the reaction read at 405nm in a microplate reader. The endotoxin concentration can be obtained from the standard curve. Each of our Chromogenic TAL endpoint assay kits is designed for two sensitivity ranges: 0.1EU/ml to 1EU/ml in a less than 20 minutes assay and 0.01EU/ml to 0.1EU/ml in a less than 1 hour assay. We also provide a diazo-coupled endpoint method for testing samples that are absorbed at 405nm, such as serum. The kits with diazo-coupled reagent were performed in test tubes, and the results were read in a spectrophotometer. Our Chromogenic TAL endpoint assay kits are comes with TAL, chromogenic substrate, Control Standard Endotoxin, TAL Reagent Water, Stopping reagent and with or without diazo-coupling reagents (everything required in the assay).