(673c) Unraveling DNA on Lipid Bilayers and Its Application for Rapid Gene Mapping

Recent studies found that DNA can spontaneously extend when confined in nanochannel with diameters smaller than few tens of nanometers. This phenomenon has been shown to have great potential for DNA analysis. However, fabrication of nanochannels requires complicated and expensive processes. It is also very difficult to get DNA into the nanochannels and to perform the following analysis.

In this study, we have developed a more efficient, low-cost, and user-friendly platform to linearize DNA at equilibrium, and applied it to rapid DNA gene analysis. In our method, DNA were first adsorbed on cationic lipid bilayers deposited on a patterned glass slide, and the adsorbed DNA spontaneously unraveled following the predefined pattern. The phenomenon is controlled by a subtle competition between the electrostatic interaction of the DNA-lipid complexes and the conformational entropy of DNA. The relative DNA extension can reach 85% of the contour lengths for both T4GT7(166kbp) and lambda DNA(48.5kbp). This value is comparable to the highest degree of DNA extension obtained in sub-50nm nanochannels. On this platform, we have successfully performed restriction mapping of lambda-DNA and T4-DNA using the restriction enzymes EcoRI, NheI, and SacI. Furthermore, we have also performed gene mapping using bis-PNA tagging and found that its accuracy can reach 200bp. Since our method is much faster and cheaper than the traditional technologies, it has great potential for future applications of DNA analysis.