Portable assay quickly monitors mushroom safety
S. Himmelstein | February 20, 2020A rapid, portable assay can take the danger out of foraging for favorite fungi. The lateral flow immunoassay (LFIA) detects the presence of as little as 10 ppb of the toxin amanitin in about 10 minutes from a small sample of a mushroom or in a person’s urine.
Antibody-based enzyme-linked immunosorbent assays and other methods available for such analysis are time-consuming and require specialized equipment. The new LFIA returns results in minutes without the use of Schematic diagram of the lateral flow strip components: (i) sample pad, (ii) conjugate pad, (iii) nitrocellulose membrane, (iv) wicking pad, (T) test line, (C) control line. The arrow indicates the flow direction. Source: Candace S. Bever et al.sophisticated laboratory equipment. The analytical approach relies on a specific reactive monoclonal antibody and requires only a sample pad, a conjugate pad, nitrocellulose membrane and a wicking pad.
The diagnostic accuracy of LFIA was demonstrated by analyzing toxin-laden urine samples and comparing results with those from liquid chromatography-mass spectrometry. Rapid analytical capabilities without the need for trained personnel render the assay appropriate for point-of-care urine testing to determine amatoxin poisoning.
The analysis is also applicable to the determination of amatoxin in dog urine, but the researchers caution that only the presence or absence of this specific class of toxin is revealed. LFIA does not detect other compounds, such as hallucinogens, and cannot determine if a mushroom is edible.
Researchers from U.S. Agricultural Research Service, U.S. Centers for Disease Control and Prevention, University of California Davis and Pet Emergency and Specialty Center of Marin (California) contributed to this study, which is published in Toxins.