Cannabis Trichomes Trigger Positive Results on Rapid Yeast & Mold Plates

Cannabis trichomes synthesize diverse collections of terpenes and antibiotic compounds likecannabinoids. Trichomes often contaminate flower homogenates utilized in cannabis microbialtesting and little is known about their effects on these platforms. To address this, we platedcannabis trichomes on multiple different plating media and observed elevated colony counts on3M™ RYM petrifilm™ plates. Further investigation revealed cannabis trichomes induce a bluecolor change with the phosphatase-based indicator dye used on 3M™ Rapid Yeast and Moldpetrifilms™. We confirmed these events with microscopy and note the color change doesn’tdilate in diameter as quickly as yeast and molds. This data implies that 3M™ Petrifilms™ maygenerate false positives compared to more traditional plating methods, if used for less than 48hours with trichome rich cannabis flowers. Longer incubation times may be necessary todifferentiate trichome derived false positives from true yeast and molds.