Electrochemical approach to distinguish bovine DNA

25 Aug 2011

Can this technique answer the need for a method to acurately identify adultered food products?

This paper presents an electrochemical way of discriminating between the DNA of different bovine species. It targets the mitochondrial Cox-1 gene which is considered to be a standard ‘barcode sequence’, having low variation within species but high degrees of variation between taxa. The benefit of targeting mitochondrial DNA is that each cell will have hundreds to thousands of copies, facilitating the use of very small samples.

Electrochemical impedance spectroscopy is central to the method and was used to probe for charge resistance transfer differences due to mismatched DNA. Zinc ions were added when DNA hybrids (matched or mismatched) formed on the gold electrode surface, expediting charge transfer to the solution phase redox probe. The zinc ions effectively adjust the charge transfer in situations where complementary sequences exist. It is therefore possible to use charge resistance transfer differences to tell if the correct DNA had been captured. The authors also carried out a dehybridization study to show if the sensor could be reused.

Find out more by reading the article for free until 4th October.

Electrochemical identification of artificial oligonucleotides related to bovine species. Potential for identification of species based on mismatches in the mitochondrial cytochrome C1 oxidase gene
Mohtashim Hassan Shamsi and Heinz-Bernhard Kraatz
Analyst
DOI: 10.1039/C1AN15414A