Rapid determination of bacteriological water quality by using limulus lysate.

The Limulus lysate assay was used to measure the endotoxin content in stream water and was found to reflect the degree of bacterial contamination as measured by coliform, enteric, gram-negative, and heterotrophic bacteria. The firm-clot method was found to be a less sensitive and reproducible technique for the detection of endotoxin than was the spectrophotometric modification of the Limulus lysate assay. Bound endotoxin, as determined by the spectrophotometric modification of the Limulus lysate assay, was found to be a better measure of the endotoxin associated with bacterial cells than was total endotoxin.