How can aflatoxins be tested in the field?

• A. Black light test under ultraviolet light showing bright fluorescence
• B. ELISA On Site Testing
• C. Gas Chromatography
• D. PCR Detection

Answer: (A)

Aflatoxins have a natural tendency to glow a blue-green color under ultraviolet light, so a handheld blacklight can be used in the field to quickly screen grains for possible contamination. This visual cue is fast, inexpensive, and requires minimal equipment—just a UV light and some samples—allowing you to quickly flag lots that look suspicious for further testing. It’s a qualitative screening method, meaning it can indicate potential contamination but doesn’t quantify how much toxin is present or confirm it definitively. Because of that, samples that fluoresce should be sent for confirmatory laboratory tests (such as ELISA, HPLC, or LC-MS) to determine actual aflatoxin levels.

Other methods are less practical in field settings: ELISA on-site can work and is more specific, but it still requires kits, reagents, and some handling steps; GC (gas chromatography) needs substantial lab infrastructure and sample prep; PCR detects fungal DNA rather than the toxin itself and doesn’t measure aflatoxin presence or amount. The UV fluorescence test provides the quickest on-site screen to decide which lots merit further testing.