Method for Estimation of Toxic Endotoxin in Inactivated Salmonella Vaccine in D-Galactosamine-Sensitized Mice

We developed a method to estimate the content of the toxic endotoxin in inactivated Salmonella vaccine in D-galactosamine-sensitized mice. Ten-fold serially diluted vaccines were injected intraperitoneally into D-galactosamine-sensitized mice. Lethality in the mice was judged 3 days after the injection. The best result was obtained when C3H/HeN mice were used for the test. Correlation was observed between the endotoxin content measured by Limulus amoebocyte lysate assay and the LD50 in the mouse safety test (r=0.81). These results suggested that this test could be applied to the estimation of endotoxin content in inactivated vaccines of Salmonella.