DNA combing on low-pressure oxygen plasma modified polysilsesquioxane substrates for single-molecule studies

摘要: Molecular combing and flow-induced stretching are the most commonly used methods to immobilize stretch DNA molecules. While both approaches require functionalization steps for substrate surface molecules, conventionally former does not take advantage of, as latter, versatility of microfluidics regarding robustness, buffer exchange capability, molecule manipulation using external forces single studies. Here, we demonstrate a simple one-step process involving only low-pressure oxygen (O2) plasma modified polysilsesquioxane (PSQ) polymer layer facilitate room temperature microfluidic device bonding immobilization stretched molecules without molecular step. Atomic force microscopy Kelvin probe experiments revealed significant increase in roughness potential on O2 treated PSQ, contrast that with high-pressure treatment, which proposed be responsible enabling effective immobilization. We further use our platform observe DNA-RNA polymerase complexes cancer drug cisplatin induced condensation wide-field fluorescence imaging.