DNA extraction method with improved efficiency and specificity using DNA methyltransferase and "click" chemistry

In an attempt to develop an alternative method to extract DNA from complex samples with much improved sensitivity and efficiency, here we report a proof-of-concept work for a new DNA extraction method using DNA methyltransferase (Mtase) and "click" chemistry. According to our preliminary data, the method has improved the current methods by (i) employing a DNA-specific enzyme, TaqI DNA Mtase, for improved selectivity, and by (ii) capturing the DNA through covalent bond to the functionalized surface, enabling a broad range of treatments yielding the final sample DNA with minimal loss and higher purity such that it will be highly compatible with downstream analyses. By employing Mtase, a highly DNA specific and efficient enzyme, and click chemistry, we demonstrated that as little as 0.1 fg of lambda-DNA (close to copy number 1) was captured on silica (Si)-based beads by forming a covalent bond between an azide group on the surface and the propargyl moiety on the DNA. This method holds promise in versatile applications where extraction of minute amounts of DNA plays critical roles such as basic and applied molecular biology research, bioforensic and biosecurity sciences, and state-of-the-art detection methods. (C) 2012 Elsevier Inc. All rights reserved.