Sensitivity of Francisella tularensis to ultrapure water and deoxycholate: implications for bacterial intracellular growth assay in macrophages.

The ability of Francisella tularensis to replicate in macrophages is critical for its pathogenesis, therefore intracellular growth assays are important tools for assessing virulence. We show that two lysis solutions commonly used in these assays, deionized water and deoxycholate in PBS, lead to highly inaccurate measurements of intracellular bacterial survival.