Inactivation of Ebola, Nipah, and Lassa viruses in tissue using neutral buffered formalin, MagMAX lysis/binding...

Samples known or suspected to be infected with high-consequence viruses such as Ebola, Nipah, and Lassa must be handled under high biocontainment. Studies involving animal infections with these pathogens can generate tissues that require downstream analyses, including molecular assays and histopathology, which are more readily performed, or in some cases only feasible, at lower containment levels. Before removal from high containment for analyses at lower containment levels, specimens must undergo validated inactivation procedures. Here, we quantified viral load reduction in tissues infected with these pathogens following treatment with neutral-buffered formalin for 10 min, 1 h, 3 days, or 7 days, and MagMAX lysis/binding solution concentrate or TriPure isolation reagent for 1 or 10 min. To ensure accurate detection of any residual infectious virus, samples were purified through resins or centrifugal filters to reduce reagent cytotoxicity and maximize volume of testable material. We demonstrated effective inactivation (≥ 4 log₁₀ reduction) of all three pathogens and quantified log-reduction values over multiple timepoints. These findings provide validation data to support safe handling of infectious tissues for research, field studies, and outbreak response.