The black and white barcodes are very familiar to everyone. Before the cashier at the supermarket, the cashier scans the barcode with the scanner, whether you buy chewing gum or beer, you can see it. But have you heard of DNA barcodes?
Fourteen years ago, scientists developed bar codes for biology, which were also used for identification. However, this barcode exists in the DNA of plants and animals. Wang Wenzhi, deputy director of the China Life Barcode South Center, said that DNA barcodes are a sequence of specific DNA fragments with sufficient variability to determine species identity.
“In short, a DNA barcode is equivalent to an identification card for a biological species and can be 100% proven to be a species.” Wang Wenzhi said that when an unknown species or part of a species is discovered, the researchers portray their DNA barcodes. Then compare it with the barcode in the international database to confirm its "identity".
DNA identification is needed in more and more fields. For example, in the case of customs transportation, when encountering animal fur, how to quickly identify whether to protect the skin of animals? After buying a wolf, how to determine if it is really a wolf? When everyone eats sushi, it is not the salmon meat... "We only need to extract a small amount of blood, muscle or hair from the organism, and we can quickly make a judgment by DNA barcode technology." Wang Wenzhi said.
To promote the development and application of DNA barcode technology, the International Life Barcode Program (iBOL) was launched in 2011. This is the world's largest biodiversity research program, and the first phase of the task – the sequencing of DNA barcodes for 5 million specimens of 500,000 species – has been completed. China has successively established the South Center and the North Center of Life Barcode, which supports the collection of large-scale DNA barcode data. Its knowledge and technology are also shared and transformed by various national nodes.
In 2016, the first edition of the English-language publication "China Science C Series" published "DNA Barcode Technology Reveals the Sale of Chinese Beef Jerky Drys". The results show that 70% of the yak meat jerky in the Chinese market is fake.
Wang Wenzhi is one of the authors of the paper. He told reporters that in 2011, the Southern Center of Life Barcode screened the yak jerky in the markets of Yunnan, Sichuan, Qinghai and Tibet. Through the 16S and COI markers, combined with the international life bar code data system, the falsification rate of these yak jerky is as high as 70%.
“The source of yak jerky is buffalo, yellow beef, pork, and even cockroaches commonly known as ‘pestivorous rats.” Wang Wenzhi told reporters.
"DNA barcode technology is a pair of eye-catching eyes, you can see the essence at a glance." Wang Wenzhi said that the food traceability of DNA is mainly through biological means, so no matter how fake, the biological properties of DNA display will not change. Practice has proved that DNA barcode technology can strictly control the safety of entrances for consumers in food traceability, especially meat products.
Due to the uniqueness and uniqueness of DNA, DNA barcode technology can be widely used in many fields. In addition to food traceability, it can also be used in judicial identification, customs, border defense, entry and exit inspection and quarantine, wildlife protection, biodiversity conservation and evaluation. DNA barcodes can be detected and identified even in dry, corrupt or physically deficient samples.
In the sensational case of the murder of the giant panda in Yunnan in 2015, the “Giant Panda” was the result of the identification of the Southern Center of Life Barcode. Wang Wenzhi told reporters that at that time, the forest police sent a piece of frozen meat for identification, suspected to be black bear meat. After identification, the meat was found to be a giant panda. “We were very surprised because there was no record of giant pandas in Yunnan. Later, we identified the bones and found it to be from a giant panda. Our identification results played an important role in the detection of the case.”