Distribution of Chemical Phenotypes (Chemotypes) in European Agricultural Hemp (Cannabis sativa L.) Cultivars

In Europe, more than 50 approved cultivars of fiber hemp (Cannabis sativa L.) are in agricultural production. Their content of psychoactive tetrahydrocannabinol (THC) is legally restricted to <0.2% (%w/w in the dry, mature inflorescences). Cannabis strains with much higher THC contents are also grown, illegally or under license for drug production. Differentiation between these two groups relies on biochemical quantification of cannabinoid contents in mature floral material. For nonflowering material or tissue devoid of cannabinoids, the genetic prediction of the chemical phenotype (chemotype) provides a suitable method of distinction. Three discrete chemotypes, depending on the ratio of THC and the noneuphoric cannabidiol (CBD), can be distinguished: a “THC-predominant” type, a “CBD-predominant” type, and an intermediate chemotype. We present a systematic genetic prediction of chemotypes of 62 agricultural hemp cultivars grown in Europe. The survey reveals the presence of up to 35% B_T allele-carrying individuals (representing either a THC-predominant or an intermediate chemotype) in some cultivars—which is unexpected considering the legal THC limit of 0.2% THC. The fact that 100% of the seized drug-type seeds in this study revealed at least one B_T allele, reflects that plant breeding efforts have resulted in a fixation of the B_T allele in recreational Cannabis. To guarantee a sincere forensic application based on a genetic chemotype prediction, we recommend not to classify material of unknown origin if the samples size is below nine genetically independent individuals.     

Simultaneous Identification of Four “Legal High” Plant Species in a Multiplex PCR High‐Resolution Melt Assay,

The international prevalence of “legal high” drugs necessitates the development of a method for their detection and identification. Herein, we describe the development and validation of a tetraplex multiplex real‐time polymerase chain reaction (PCR) assay used to simultaneously identify morning glory, jimson weed, Hawaiian woodrose, and marijuana detected by high‐resolution melt using LCGreen Plus^®. The PCR assay was evaluated based on the following: (i) specificity and selectivity—primers were tested on DNA extracted from 30 species and simulated forensic samples, (ii) sensitivity—serial dilutions of the target DNA were prepared, and (iii) reproducibility and reliability—sample replicates were tested and remelted on different days. The assay is ideal for cases in which inexpensive assays are needed to quickly detect and identify trace biological material present on drug paraphernalia that is too compromised for botanical microscopic identification and for which analysts are unfamiliar with the morphology of the emerging “legal high” species.     

The detection and persistence of Cannabis sativa DNA on skin

The presence of Cannabis sativa DNA was detected on the skin of persons who have recently handled both leaf and resinous material. The persistence of C. sativa DNA was examined on the skin. The subjects were asked to either repeatedly rub their hands on their trousers, place their hands repeatedly into their pockets or wash their hands in soap and water. After rubbing the hands on trousers or placing them in pockets C. sativa DNA could still be detected. No DNA could be detected after washing the hands.     

Sibling Abuse in Nature and Culture

This essay reflects on an article by Katy Butler in the Science Section of the New York Times of February 28, 2006. It argues that Butler discusses sibling abuse mainly as a biologically rooted phenomenon and does not clarify its social sources and dynamics. The essay presents the social causes of sibling abuse and suggests approaches toward its short‐term reduction and long‐term prevention.     

Packed column chromatography, high-resolution gas-chromatography and high pressure liquid chromatography in comparison for the analysis of cannabis constituents

The identification and the quantitative estimation of cannabis constituents is important for forensic purposes. High resolution gas-chromatography gives better results than gas-liquid chromatography with packed columns, as it shows a better resolution and higher number of constituents. Different quantitative values were found with the two chromatographic procedures. High-pressure liquid chromatography revealed the presence of cannabinoid acids in fresh cut influorescences of cannabis plants. The ratio acid/neutral cannabinoid may be useful in supplying information about the age of the cannabis preparations.     

A Cannabis sativa STR Genotype Database for Australian Seizures: Forensic Applications and Limitations*

Abstract: A genetic database was established with the aim of documenting the genetic diversity of Cannabis sativa in Australia for future utilization in forensic investigations. The database consisted of genotypes at 10 validated short tandem repeat loci for 510 plants representing drug seizures from across Australia and 57 fiber samples. A total of 106 alleles and 314 different genotypes were detected. All fiber samples exhibited unique genotypes while 55% of the drug samples shared a genotype with one or more samples. Shared genotypes were mostly found within seizures; however, some genotypes were found among seizures. Statistical analysis indicated that genotype sharing was a consequence of clonal propagation rather than a lack of genetic resolution. Thus, the finding of shared genotypes among seizures is likely due to either a common supplier, or direct links among seizures. Notwithstanding the potential intelligence information provided by genetic analysis of C. sativa, our database analysis also reveals some present limitations.     

Human olfactory detection of packaged cannabis

Olfactory detection of cannabis aroma by police officers can be the basis for warrantless searches of motor vehicles in many jurisdictions in the United States. The odor source in these cases is often dried cannabis flower contained in various casual wrappings as well as in more elaborate packaging. Here we investigate whether packaging format alters the detectability of the cannabis. Two cannabis strains and five packaging formats were evaluated. Untrained observers were presented with two containers and asked to identify, based only on smell, the container that held a sample of packaged cannabis (the other container held identical, but empty, packaging material). The results showed that open and casually packaged cannabis was identified with high accuracy, while material packaged in doubly vacuum-sealed plastic was correctly identified at rates no different from chance. The results may help address issues involving the detectability of cannabis aroma in law enforcement and other scenarios.     

大麻的DNA分析检验技术

本文简要回顾了大麻的一些常规检验方法,并重点综述了大麻植物的DNA分析检验技术,包括随机扩增多态性DNA(RAPD)、测序扩增区段(SCAR)、短串联重复序列(STR)、扩增片段长度多态性(AFLP)、单核苷酸多态性(SNP)等DNA分子标记检测法。并且对这几种技术的应用范围及前景做了简要分析,以期为实践工作提供基础理论帮助。     

Drugs in oral fluid in randomly selected drivers

There were 13,176 roadside drug tests performed in the first year of the random drug-testing program conducted in the state of Victoria. Drugs targeted in the testing were methamphetamines and Δ⁹-tetrahydrocannabinol (THC). On-site screening was conducted by the police using DrugWipe^®, while the driver was still in the vehicle and if positive, a second test on collected oral fluid, using the Rapiscan^®, was performed in a specially outfitted “drug bus” located adjacent to the testing area. Oral fluid on presumptive positive cases was sent to the laboratory for confirmation with limits of quantification of 5, 5, and 2 ng/mL for methamphetamine (MA), methylenedioxy-methamphetamine (MDMA), and THC, respectively. Recovery experiments conducted in the laboratory showed quantitative recovery of analytes from the collector. When oral fluid could not be collected, blood was taken from the driver and sent to the laboratory for confirmation. These roadside tests gave 313 positive cases following GC–MS confirmation. These comprised 269, 118, and 87 cases positive to MA, MDMA, and THC, respectively. The median oral concentrations (undiluted) of MA, MDMA, and THC was 1136, 2724, and 81 ng/mL. The overall drug positive rate was 2.4% of the screened population. This rate was highest in drivers of cars (2.8%). The average age of drivers detected with a positive drug reading was 28 years. Large vehicle (trucks over 4.5 t) drivers were older; on average at 38 years. Females accounted for 19% of all positives, although none of the positive truck drivers were female. There was one false positive to cannabis when the results of both on-site devices were considered and four to methamphetamines.     

Cannabis sales and immigrant youth gangs in Denmark – An exploratory study of market structure and youth gang evolution

Cannabis sales by youth gangs consisting of male descendants of immigrants from Middle Eastern countries are subject of much public debate in Denmark and Scandinavia. Only little research has explored the intersection between the wider social context of the drug market and the criminal engagements of these groups using qualitative methods. Using eleven semi-structured interviews with youth, police and experts, collected between 2011 and 2013, this study examines how the overall structure of the cannabis market in Copenhagen affects the opportunities to engage in cannabis sales for immigrant youth gangs. The study rests on an assumption that increased deterrence in specific geographic areas will displace buyers and shift market shares between competing groups. The result was that increased cannabis dealing furthered gang evolution even at the lowest organizational steps, from neighbourhood groups to more delinquent collectives. A key finding is that neighbourhood youth clubs play a central role in the lives of the interviewees. Youth clubs served as social spaces but also functioned as a form of turf to be conquered from city officials.