On June 4, 2020, the U.S. Food and Drug Administration (FDA) issued a letter to clinical laboratory staff and health care providers reminding them to use appropriate transport media with SARS-CoV-2 tests. The letter states:
“There is a risk of exposure to harmful cyanide gas, a by-product of a reaction between guanidine thiocyanate or similar chemicals and bleach (sodium hypochlorite), when certain transport media are used with an incompatible testing platform or laboratory process. Guanidine thiocyanate may be referred to as guanidinium rhodanide, guanidinium thiocyanate, or guanidinium.”
The letter goes on to name several sample collection devices that utilize guanidine thiocyanate or similar chemicals and states that they should not be used with specific testing platforms or in any laboratory that uses bleach…
“When the bleach interacts with the guanidine thiocyanate or similar chemicals in the transport media, it produces cyanide gas.”
DNA Genotek recommends the OMNIgene®·ORAL (OME-505) and ORAcollect®·RNA (OR-100 and ORE-100) collection and stabilization devices for SARS-CoV-2 (COVID-19) testing. The chemistries in these devices are designed to lyse cells and denature/degrade proteins while keeping the RNA stable by inactivating nucleases and inhibiting microbial growth.
Although the complete formulation of our chemistry is proprietary, we can state that DNA Genotek collection devices and chemistries do not contain guanidinium, unlike stabilization chemistries used in other collection devices.
If you are using a collection device from a manufacturer other than DNA Genotek, we recommend you follow the advice in the FDA letter which states:
“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. If laboratory staff receive samples in unfamiliar transport media, or transport media without appropriate labeling, they should make sure the media does not contain guanidine thiocyanate or similar chemicals before processing the samples in a testing platform that uses bleach, or before using the samples in a laboratory that regularly uses bleach for laboratory cleaning and decontamination processes.”