Discrimination of 'fiber-type' and 'drug-type' Cannabis sativa L. by fluorescent duplex PCR

A fluorescent duplex-PCR test was developed based on polymorphisms of the THCA synthase gene in order to discriminate the fiber- and drug-type Cannabis sativa L. and to indicate the presence of Cannabis trace in suspected materials by the numbers and sizes of PCR-amplified products. DNA analysis of drug-type Cannabis resulted in two different PCR-amplified DNA fragments of 94 and 158. bp, whereas only the 94. bp PCR product was amplified from the fiber-type DNA. DNA test results of another 6 Cannabis sativa L. collected from the field agreed with chemotype determined by GC-MS. However, it was noted that the only intermediate drug-type sample tested gave a drug-type result for DNA testing. Specificity of the duplex PCR was shown by testing with DNA from species that may be related to Cannabis abuse, i.e., common hop (Humulus lupulus L.), 2 narcotic plants (Papaver somniferum and Mitragyna speciosa), tobacco (Nicotiana tabacum) and human. Sensitivity of detection was as low as 100. pg of genomic DNA.