The current technique for the detection of fetus genotype by in-vitro fertilization (IVF) is quite expensive and is unsuitable/ inconvenient for all patients and even affects the embryonic growth cycle. We thus propose a new method to extract small amount of cell-free DNA (cf-DNA) from embryo culture medium. We introduce a new format for DNA extraction depending on digital microfluidics (DMF), electrowetting-on-dielectric (EWOD) and magnetic forces to separate, suspend DNA-coated magnetic particles. Nano-droplets (of nano-liter size) are electrostatically controlled on an array of insulated electrodes by EWOD system. By applying voltage to the various electrodes, multiple nano-droplets can be manipulated precisely in the same device. This feature enables one to extract DNA at ultra-small concentrations (fg/μL to pg/μL) from an embryo culture medium with an EWOD system. We applied our EWOD platform to extract a small amount of cf-DNA from a clinical embryo culture medium of mouse. In the future, we will distinguish the DNA in the real embryo buffer according to the length of the telomere. This feature would be valuable for the selection of an embryo before an implantation when the gene information can be recognized.

用于通过体外受精（IVF）检测胎儿基因型的当前技术是相当昂贵的，并且不适用于所有患者/不方便所有患者，甚至影响胚胎生长周期。因此，我们提出了一种从胚胎培养基中提取少量无细胞DNA（cf-DNA）的新方法。我们引入了一种新的DNA提取格式，具体取决于数字微流体（DMF），电介质上电润湿（EWOD）和磁力来分离，悬浮DNA包覆的磁性颗粒。纳米液滴（纳升大小）通过EWOD系统在一系列绝缘电极上进行静电控制。通过向各个电极施加电压，可以在同一设备中精确地操纵多个纳米液滴。这一功能使人们可以使用EWOD系统从胚胎培养基中提取超低浓度（fg /μL至pg /μL）的DNA。我们使用EWOD平台从小鼠的临床胚胎培养基中提取了少量的cf-DNA。将来，我们将根据端粒的长度区分真实胚胎缓冲液中的DNA。当可以识别基因信息时，此功能对于植入前的胚胎选择非常有价值。