Some toxic mushrooms look a lot like some edible mushrooms.


Candace Bever, ARS-USDA

Springtime amanita mushrooms are delicious, but they look a lot like toxic death cap mushrooms. For foragers, knowing the difference is critical. It’s also key for doctors working to diagnose patients with mushroom poisoning.¬†

Researchers with the United States Department of Agriculture’s Agricultural Research Service (ARS) have developed a portable test that can detect trace amounts of amanitin, the class of toxin found in some of the world’s most deadly mushrooms.

The test can work on a mushroom sample the size of a grain of rice, or it can be used to detect the toxin in human or dog urine. “We developed the test primarily for mushrooms as food products. Serendipitously, it was sensitive enough to also detect the toxin in urine,” said ARS microbiologist Candace Bever in a USDA release on Wednesday. It take about 10 minutes for the test to return a result.

Consuming toxic mushrooms leads to over 100 deaths a year globally, according to the USDA. Thousands more are sickened and require medical care. Mushroom poisoning can lead to severe gastrointestinal issues and liver and kidney damage.

“Our hope is that doctors and veterinarians will be able to quickly and confidently identify amatoxin poisoning rather than having to clinically eliminate other suspected gastrointestinal diseases first,” said Bever.

The test is not currently available for recreational mushroom hunters, but the USDA said it could be “a practical and definitive way for mushroom foragers to identify and avoid eating mushrooms with amanitin toxin if a commercial partner can be found to produce and market a test kit.”

The ARS team published a paper on the test in the journal Toxins this month. 

The USDA cautions that the test will only identify the presence or absence of the toxin. It can’t detect hallucinogens or determine if a mushroom is edible. Even if it arrives on the market as a test kit, foragers will still need to know their mushrooms.