Improvements in the passive immune hemolysis test for assaying enterotoxigenic Escherichia coli

The sensitivity of the passive immune hemolysis test for the detection of heat-labile enterotoxin from Escherichia coli was increased when the test was carried out with Veronal-buffered saline plus Ca2+ and Mg2+ as diluent, instead of phosphate-buffered saline. The performance of the test was further improved by using stationary cultures to which mitomycin C had been added at the end of the lag phase.