Featured Research

from universities, journals, and other organizations

New DNA 'Fingerprinting' Technique Separates Hemp From Marijuana

Date:
March 23, 2006
Source:
University of Minnesota
Summary:
Using new DNA "fingerprinting" techniques, two University of Minnesota researchers have become the first to unequivocally separate hemp plants from marijuana plants with genetic markers.

Using new DNA "fingerprinting" techniques, two University of Minnesota researchers have become the first to unequivocally separate hemp plants from marijuana plants with genetic markers. Hemp, a crop grown for durable fiber and nutritious seed, and marijuana, the most abundant illegal drug of abuse in the United States, both belong to the species Cannabis sativa. They differ in levels of the psychoactive drug tetrahydrocannabinol (THC) but are otherwise difficult to tell apart. The technique holds promise for distinguishing different cultivars (domesticated plant lines) in U.S. criminal cases. It may also prove useful in countries where the cultivation of hemp is permitted but marijuana is illegal, as in Canada and Europe. The work appears in the March issue (volume 51, No. 2) of the Journal of Forensic Science.

Related Articles


The new technique is an improvement on previous means of separating the two types of Cannabis, said author George Weiblen, an assistant professor of plant biology in the university's College of Biological Sciences and College of Food, Agricultural and Natural Resource Sciences. For decades it has been possible to identify THC chemically, but the drug is not present in all plant tissues or throughout a plant's life cycle. And other researchers have found that genetic markers known as "short tandem repeats," which are used to identify individuals in paternity and criminal cases, lack the power to distinguish Cannabis cultivars unequivocally.

In tests with three different cultivars of hemp and one of marijuana, the DNA fingerprints of all the cultivars were distinct and nonoverlapping. Weiblen and Shannon L. Datwyler, a postdoctoral associate who is now on the faculty of California State University, Sacramento, found that the AFLP (amplified fragment length polymorphism) technique generated hundreds of genetic markers that together established separate identities for each of the four cultivars.

"We think this technique has the potential to distinguish marijuana varieties as well," said Weiblen. "It has implications not just for separating hemp from marijuana in countries where hemp cultivation is permitted, but in establishing origins of seized drugs and, therefore, conspiracy in drug distribution networks. It also could be used in criminal defenses against claims of conspiracy."

The technique chops up DNA and generates numerous fragments of DNA, each defined by particular "marker" DNA sequences that act like bookends. The lengths of the fragments within the bookends were found to vary according to the cultivar. Thus, the pattern of fragment lengths adds up to a composite picture of each cultivar.

"With this technique, we find hundreds of markers scattered across the genome," said Weiblen. "The larger number of markers, compared to other techniques, gives us the power to separate the cultivars."

The Cannabis plant has been cultivated for millennia and is important in the global economy as both a licit and an illicit crop, said Weiblen. Hemp is a source of durable fiber that provides an alternative to cotton fabric, among other uses. Cotton requires pesticide application and a hot climate, whereas hemp does not, which makes it suitable for local Minnesota agriculture. Weiblen seeks to screen a wider range of Cannabis cultivars to refine the technique. He is also working to identify regions of the Cannabis genome responsible for drug content in marijuana. If enough can be learned about the genome, it may one day be possible to produce an entirely drug-free hemp plant that looks different from marijuana. Currently, all hemp products are imported into the United States. Developing a new variety that could be cultivated in the United States would reduce American dependence on foreign products while creating a new alternative crop for American farmers.

The work was funded by the University of Minnesota and the David and Lucille Packard Foundation.



Story Source:

The above story is based on materials provided by University of Minnesota. Note: Materials may be edited for content and length.


Cite This Page:

University of Minnesota. "New DNA 'Fingerprinting' Technique Separates Hemp From Marijuana." ScienceDaily. ScienceDaily, 23 March 2006. <www.sciencedaily.com/releases/2006/03/060322135105.htm>.
University of Minnesota. (2006, March 23). New DNA 'Fingerprinting' Technique Separates Hemp From Marijuana. ScienceDaily. Retrieved November 28, 2014 from www.sciencedaily.com/releases/2006/03/060322135105.htm
University of Minnesota. "New DNA 'Fingerprinting' Technique Separates Hemp From Marijuana." ScienceDaily. www.sciencedaily.com/releases/2006/03/060322135105.htm (accessed November 28, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Friday, November 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

New Dinosaur Species Found in Museum Collection

New Dinosaur Species Found in Museum Collection

Reuters - Innovations Video Online (Nov. 27, 2014) A British palaeontologist has discovered a new species of dinosaur while studying fossils in a Canadian museum. Pentaceratops aquilonius was related to Triceratops and lived at the end of the Cretaceous Period, around 75 million years ago. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Classic Hollywood Memorabilia Goes Under the Hammer

Classic Hollywood Memorabilia Goes Under the Hammer

Reuters - Entertainment Video Online (Nov. 26, 2014) The iconic piano from "Casablanca" and the Cowardly Lion suit from "The Wizard of Oz" fetch millions at auction. Sara Hemrajani reports. Video provided by Reuters
Powered by NewsLook.com
Pet Dogs to Be Used in Anti-Ageing Trial

Pet Dogs to Be Used in Anti-Ageing Trial

Reuters - Innovations Video Online (Nov. 26, 2014) Researchers in the United States are preparing to discover whether a drug commonly used in human organ transplants can extend the lifespan and health quality of pet dogs. Video provided by Reuters
Powered by NewsLook.com
From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

Newsy (Nov. 25, 2014) The US FDA is announcing new calorie rules on Tuesday that will require everywhere from theaters to vending machines to include calorie counts. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins