Transport media is the liquid that maintains a specimen sample while it is transported to a laboratory. The Hologic Panther systems and others that have been sterilized using bleach can interact with transport media containing guanidine thiocyanate or similar chemicals to produce deadly cyanide gas, according to the agency. Guanidine thiocyanate may be referred to as guanidinium rhodanide, guanidinium thiocyanate or guanidinium.
While there have been reports of these potentially hazardous interactions, there have been no injuries reported to the FDA associated with exposure to cyanide gas as a result of using incompatible media with testing platforms.
Numerous transport media contain guanidine thiocyanate or similar chemicals, including PrimeStore molecular transport media (MTM) (LH-1-02 and LH-1-03), Zymo DNA/RNA Shield and Spectrum Solutions Saliva Collection Device, the agency noted. Laboratories that use bleach as part of their normal laboratory processes should also not use the Hologic Panther and Panther Fusion systems, the FDA warned.
The production of those Hologic testing systems includes a disinfecting step involving bleach, according to the agency, which added that some ingredients in transport media may not be listed on individual tubes. If laboratory staff do not know the ingredients in the transport media, they should handle it as though it has guanidine thiocyanate or similar chemicals to avoid a potential reaction, the agency warned.
The FDA-approved instrument operator manual for Hologic Panther and Panther Fusion systems includes a prominent warning against using any media containing guanidine compounds, company spokesperson Suzanne Clancy told MassDevice in an email.
Hologic also sent customers a technical bulletin about the risk in April and added language to assay package inserts in April to remind customers of the FDA warning, Clancy said.
The FDA said it working with manufacturers of transport media and SARS-CoV-2 testing platforms to improve product labeling. It is also working with federal and state health agencies to inform laboratory staff about the risk.