Maki Wusi C, Mishra Nirankar N, Cameron Eric G, Filanoski Brian, Rastogi Shiva K, Maki Gary K
Center for Advanced Microelectronics and Biomolecular Research, University of Idaho, Post Falls, Idaho, USA.
Biosens Bioelectron. 2008 Jan 18;23(6):780-7. doi: 10.1016/j.bios.2007.08.017. Epub 2007 Aug 30.
Accurate detection of DNA methylation at specific gene transcription sites is important to identify potential tumor formation since this epigenetic alteration may result in silencing of tumor suppressor genes that protect against tumor formation or that repair damaged DNA. Current technologies used in DNA methylation detection are complicated and time consuming. This work presents the first nanowire field effect transistor (FET) based biosensor technology which achieves simple and ultra-sensitive electronic DNA methylation detection and avoids complicated bisulfite treatment and PCR amplification. The promoter of the p16(INK) gene, a tumor suppressor gene, is the target DNA in the detection model. The target DNA was captured and concentrated with magnetic beads, and released to the sensing surface of a nano-FET through a reversible binding process. The methylated p16(INK) promoter was recognized and bound to monoclonal anti-5-methylcytosine antibodies which were immobilized on the nano-FET sensing surface. The presence of the target DNA molecules induced electronic charge and changed the electronic properties of the nano-transistor from which detectable electronic signals are generated. The electronic charge based DNA methylation detection is simple and ultra-sensitive with the potential for low cost. The detection sensitivity was achieved at 2.5 x 10(-19) mol with no false positives observed.
准确检测特定基因转录位点的DNA甲基化对于识别潜在的肿瘤形成非常重要，因为这种表观遗传改变可能导致抑癌基因沉默，这些抑癌基因可预防肿瘤形成或修复受损的DNA。目前用于DNA甲基化检测的技术复杂且耗时。这项工作展示了首个基于纳米线场效应晶体管（FET）的生物传感器技术，该技术实现了简单且超灵敏的电子DNA甲基化检测，避免了复杂的亚硫酸氢盐处理和PCR扩增。检测模型中的靶DNA是肿瘤抑制基因p16（INK）的启动子。靶DNA用磁珠捕获并浓缩，然后通过可逆结合过程释放到纳米FET的传感表面。甲基化的p16（INK）启动子被识别并与固定在纳米FET传感表面的抗5-甲基胞嘧啶单克隆抗体结合。靶DNA分子的存在会感应电荷并改变纳米晶体管的电学性质，从而产生可检测的电信号。基于电荷的DNA甲基化检测简单、超灵敏且具有低成本潜力。检测灵敏度达到2.5×10（-19）mol，未观察到假阳性。
