dna barcode (2)


CRISPR (clustered regularly interspaced short palindromic repeats)-Cas(CRISPR-associated protein) is derived from a microbial antiviral system and is commonly associated with cutting edge gene editing. However, the system can also be adapted for diagnostic applications inclusive of novel approaches for food authenticity and adulteration testing.

In this paper, the Chinese research team coupled PCR amplification with a CRISPR-Cas12a based colorimetric system to indicate the presence of DNA barcoding targets by a visible colour change. The whole detection process including PCR amplification and TMB ( 3,3′,5,5′-tetramethylbenzidine sulfate) colorimetric analysis can be completed within 90 minutes.This sensitive assay was verified by the identification of four important species of pufferfish,

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The Caribbean Red Snapper (Pargo) Lutjanus purpureus is the most economically important snapper in Brazil, which is sold, among other forms, as frozen fillets. 142 samples were collected between March 2013 to October 2014 from supermarkets in the State of Pará, North Brazil, which were processed by a single supplier. These were analysed using a DNA method, which sequenced a 600-bp fragment corresponding to the barcode portion of COI gene  to identify the fillets, with the aid of sequences from the public and control databases. Only L. purpureus and L. campechanus can be denominated “Pargo” in Brazil, but the results found that 22% of the samples were Rhomboplites aurorubens, a snapper with low commercial value in the country, revealing commercial fraud.

  Read the full paper at: Caribbean red snapper substitution

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