Possible Biohazard Risk from Infectious Tissue and Culture Cells Preserved with RNAlater™

Abstract

When freezing facilities for biological materials are not available, there is a need for fixatives that allow the examination of single samples for morphological as well as antigen, antibody, or nucleic acid analyses. A widely used stabilization buffer, RNA later ™ RNA Stabilization Reagent (Qiagen), has been assessed in clinical tissues and compared with snap-freezing (1) for use in RNA preservation for quantitative RNA expression studies and histologic and immunohistochemical investigations(2). Protection of flavivirus antigen was demonstrated by antigen-capture ELISA(3), and antibody assays have been completed using RNA later -preserved materials(4). According to the manufacturer the lack of RNA later toxicity makes the product user-friendly for sample transportation, but biological safety may still be a concern with some RNA later -treated specimens. Picornavirus, rhabdovirus, and HIV in cell culture supernatants retain infectivity after RNA later stabilization(5). The study described here evaluates the risk of remaining poxvirus infectivity from cultured cells and tissue specimens fixed with RNA later at various temperatures mimicking field conditions. Semiconfluent Hep2 cells were infected with an orthopoxvirus (vaccinia virus, VV, strain NYCDH) at …