The endotoxin test is a gel clot assay used to determine whether the test samples contain specific amounts of endotoxin. The sample and the limulus amebocyte lysate (LAL) reagent solution are mixed in an endotoxin-free tube and incubated at 37°C for 60 min. After the incubation, the tube is tilted to see whether the mixture clots. If the sample contains less endotoxin than the standard,the solution remains liquid; whilst if the endotoxin amount is higher than the standard, the mixture will clot at the bottom of the tube.
