AVS 56th International Symposium & Exhibition
    Biomaterial Interfaces Wednesday Sessions
       Session BI+AS+BM+MS-WeM

Paper BI+AS+BM+MS-WeM12
Nanomechanical Readout of DNA Microarrays

Wednesday, November 11, 2009, 11:40 am, Room K

Session: Array-Based Sensors and Diagnostics: Grand Challenges
Presenter: H.H.J. Persson, Stanford University
Authors: S. Husale, Rowland Institute at Harvard University
H.H.J. Persson, Stanford University
O. Sahin, Rowland Institute at Harvard University
Correspondent: Click to Email
DNA microarrays have enabled high throughput analysis of gene-expression and genotyping. However, they still suffer from limited dynamic range and rely heavily on enzymatic manipulations and amplification to create detectable signals. Here we present application of a novel nanomechanical detection method to microarray analysis that may circumvent these disadvantages. It is based upon a modified atomic force microscope (AFM) that can map mechanical properties of surfaces at high speed and spatial resolution. Mechanical measurements can reliably discriminate single and double stranded DNA on a surface. Automated image analysis reveals hybridized molecules with single molecule precision, thus providing a digital measure of hybridization. This method can detect a broad range of target concentrations with a limit of detection in the low attomolar concentration range without any labeling, enzymatic manipulations, and amplification. We demonstrate the performance of this technique by measuring differential expressions of miRNAs in tumor samples, which has been shown to help discriminate tissue origins of metastatic tumors.