Recently, the United States Department of Agriculture developed a lateral flow immunoassay for the qualitative detection of amatoxins which is available commercially and is sold as AMATOXtest. Amatoxins are potent RNA polymerase II inhibitors. After ingestion, they cause gastrointestinal upset and ultimately lead to liver damage and death. The immunoassay test is designed for the qualitative determination of amanitin in a mushroom extract as well as a urine sample. This test is presently considered as 'research use only' and is not to be used for therapeutic or diagnostic purposes.
The AMATOXtest works like other simple immunoassay tests that are familiar to the clinical laboratory. The test is very similar in design to a common pregnancy test. The user tears off a small portion of the mushroom cap (about the size of a nail clipping) and places it in a test tube or Eppendorf tube then adds enough room temperature water to fill the tube halfway. The cap is then fixed and the tube is shaken for about 30 seconds. Then a disposable pipette is used to draw up some of the extract and three drops are placed within the circular opening in the test cassette. After 10 minutes, the test device is read. If two lines appear in the window then the test is negative for amanitin. If only one red line appears in the window the test is positive (See diagram below). Be aware that the results are opposite of common lateral flow assays such as pregnancy tests or COVID-19 antigen tests.
NOTE: THE AMATOXtest IS NOT A TEST TO SEE IF A MUSHROOM IS EDIBLE OR NOT. A MUSHROOM THAT GIVES A NEGATIVE TEST MAY CONTAIN ONE OF THE OTHER POISONOUS TOXINS. A NEGATIVE TEST ONLY MEANS THAT THE MUSHROOM IS NEGATIVE FOR THE TOXIN AMANITIN.
