Gel Clot LAL (PYROGENT™) provides a simple positive/negative result and is most often mentioned in pharmacopeial monographs as the official referee test.
Lonza’s PYROGENT™ Gel Clot LAL Assay is a qualitative LAL test for Gram-negative bacterial endotoxin. The gel clot assay is run in tubes that are placed in a water bath or dry heat block at 37°C. After a one-hour incubation period, the tubes are flipped 180°. A firm clot that stays in the bottom of the tube indicates a positive reaction. If liquid flows down the side of the tube, the result is negative for endotoxin.