Plastics, endotoxins, and the Limulus amebocyte lysate test.

A variety of polypropylene and polystyrene tubes have been tested for use with the Limulus amebocyte lysate (LAL) test. Polypropylene tubes tended to be more contaminated with endotoxin than polystyrene. One brand of polypropylene tube contained a water extractable inhibitor of the LAL test. Polystyrene tubes from some manufacturers caused enhancement of the LAL test. Other polystyrene tubes were not significantly different from glass for storage of endotoxin or dilution water. Results of these studies indicate that while some tubes are well suited for use with the LAL test, others are not.