DNA barcoding recently hit the headlines with the publication of a paper by Prof Steven Newmaster and his group at the Guelph-based Biodiversity Institute of Ontario. DNA analysis of 44 herbal products sold by 12 companies indicated that nearly 60% of the herbal products contained plant species not listed on the label, and product substitution was detected in 32% of the samples.
(Barcodes are short genetic markers or signatures in DNA that identify which particular species it belongs to.)
In response to the paper, which was published in the open access journal BMC Medicine, leading industry figures were quick to point out the limitations and flaws. The American Botanical Council has gone so far as to call for a retraction of the paper (to read the extensive ABC critique, please click here). Others industry sources, however, questioned if DNA barcoding is yet fit for purpose.
One of the co-authors of the ABC critique, Danica Harbaugh Reynaud, PhD, a geneticist, botanical taxonomist, and CEO of Richmond, CA-based AuthenTechnologies strongly dismisses such questions about reliability and being fit for purpose: “DNA barcoding is very reliable,” she told us. “It’s used throughout many industries. People go to jail because of it.
“My critique of the Newmaster paper is that the authors didn’t take the necessary precautions to have reliable data. Whatever the test is, it needs to be done correctly.”
“DNA barcoding is most definitely reliable, but only when performed on appropriate material,” she said. “For testing, there needs to be DNA present!”
Botanical extracts (as were allegedly used in the Newmaster et al. paper) are not appropriate, she said. “The extraction processes eliminate the cellular material, and there is no evidence that DNA can be obtained from botanical extracts.”
Every cloud has a silver lining?
Despite the negativity surrounding the conclusions of the study, Dr Reynaud said that the paper may eventually be a good thing for the industry since it has focused attention even more on quality standards. It has already been good for AuthenTechnologies, she said, with companies calling with concerns about the alleged high levels of contamination or substitution.
“The paper has generated greater awareness and acceptance of DNA barcoding,” she said.
“I’m a proponent of good science, and you should only do DNA testing if you’re going to do it right.”
Analytical experts have noted that DNA authentication of botanicals requires extensive expertise in both DNA analysis as well as taxonomy/botany. Having expertise in botany is key, said Dr Reynaud, who obtained her bachelor’s and doctoral degrees in integrative biology, focusing on botanical genetics and taxonomy, from the University of California – Berkeley.
Following a post-doctoral research position at the Smithsonian, and working briefly at a botanical drug company, Bionovo, Inc., Dr Reynaud founded AuthenTechnologies in 2010. “DNA authentication was not widely adopted in the industry and no-one was offering these services,” she said.
Almost four years on, is the situation different? “Yes, big time,” she said. “We’re working with some of the biggest companies in this space. We’re over-run with business.
“It may be really surprising, but we have no competitors, or at least we don’t know of any competitors, anywhere in the world.”
And the next two to three years will see a bigger shift again, she said. “More companies want DNA barcoding, and we plan to open satellite offices in the Mid-West and East Coast. We want a tight one-on-one relationship with customers.”
Adulteration & reference materials
While the levels of substitution and contamination identified in the Newmaster paper have been described as excessive, Dr Reynaud said the company does finds a lot of substitution in products with closely-related species that chemistry cannot identify. Relying exclusively on the chemical tests would not reveal this substitution, and DNA barcoding shouldn’t replace other methods but contribute to the overall ingredient identity and quality testing.
Another issue that Dr Reynaud and her team have identified is with some reference materials. “We’re finding that some reference materials are wrong. Everyone is relying on reference materials, but some are incorrect.”
In response to this, the company has already developed the first line of DNA-Authenticated Botanical Identity Reference Materials (DNA-BIRMs), along with value-added DNA-barcodes for currently available and new NIST botanical powder Standard Reference Materials, which will be released early in 2014.
“Most of what we do is education,” she said. “Everyone we talk to gets on board. We don’t do any sales or marketing or advertising, all of our business has been via word of mouth.” A particularly fruitful approach has been engaging with select organizations, and the company is a member of ABC, UNPA, IFT, ASTA, and NPA.
So what does all this cost? “The target is to make it routine and not for price to be a factor,” said Dr Reynaud. “Current routine clients pay around $250 per test, which is on a par with other higher-end analytical testing.”