Teas are made from leaves of the tea plant, Camellia sinensis; herbal infusions, which are often called "teas," use the roots, leaves, stems, seeds, or flowers of many different plants. But appearance does not easily identify the bits of dried plants, which sometimes are also cooked or fermented, that are used to prepare infusions and teas. The researchers found the plant DNA extremely resilient and obtained barcodes from 90 percent of the 146 products sampled
The products, half teas and half herbals, from 33 different manufacturers spanning 17 countries, were collected or purchased at 25 locations in New York City including stores, school dining halls, and the homes of the investigators.
Some of the DNA extractions and amplifications were carried out on a dining room table in the apartment of mentor and barcoding expert Mark Stoeckle, an adjunct faculty member with the Program for the Human Environment at The Rockefeller University.
The lab equipment was purchased used on the Internet for about $5,000, highlighting the viability of public DNA-based plant identification. After extracting and amplifying the DNA in the home lab, the samples were mailed to a commercial DNA sequencing facility. The total cost was about $15 per sample and took about 24 hours in total.
Most of the DNA analysis was done at The New York Botanical Garden. When the students obtained a DNA sequence, they checked it using the GenBank DNA database maintained by the US National Library of Medicine, that retrieves matching sequences and candidate species names almost instantly.
"These results demonstrate a low-cost approach for plant identification that could be used in educational, regulatory, and research settings to produce practical inf
|Contact: Zach Veilleux|