Fig. 2: Detection of cannabinoids with the fluorescent output cannabinoid biosensor.

a Incubation of the cannabinoid biosensor strain in the absence of CB₂ receptor (KM201, light gray) with up to 1 μM CP55940 resulted in no increase of the fluorescent output. Inducing biosensor strain KM202 expressing CB₂ receptor (dark gray) with 10 pM to 1 μM CP55940 resulted in a typical sigmoidal dose–response curve revealing an apparent EC₅₀ of 15 nM. Strain KM203 (black) producing CB₂ fused with the mating factor α signal sequence (MFaSS-CB₂) showed higher sensitivity (EC₅₀ = 4.6 nM). b When the above-mentioned strains were incubated with THC, KM203 (black) showed higher sensitivity (EC₅₀ = 1.2 µM) than KM202 (dark gray), which displayed an apparent EC₅₀ of 1.8 µM. The control strain, KM201 (light gray), was not induced by the cannabinoid. c The biosensor was also incubated with JWH-18. For KM202, EC₅₀ was determined to be 370 nM, while for KM203, EC₅₀ was 169 nM. The control, KM201 was not induced by JWH-018. Data presented as mean + /− standard deviation. n = 3 biologically independent samples. Source data are provided in the Source Data file.