微流控芯片技术用于精子与上皮细胞分离的研究

为研究建立使用微流控芯片技术分离精子与阴道上皮细胞的方法，选用制作工艺简单的玻璃-PDMS芯片，对混合样本进行分离。加样前分别在进、出口池中加入7此和lO此缓冲液，然后在进样口加入2此混合样本。至少静置8nlin后，从出口池中取出3此形成重力驱动的微流体后开始分离，每隔5min在进样口补加1此缓冲液。达到理想分离效果时，用移液器从出口池取出分离出的精子，核酸酶去除游离DNA，经过提取、扩增和电泳分离脸测等步骤得到精子的分型结果。结果显示，使用基于重力驱动微流体原理的微流控芯片可在30min内分离出精子，不会有上皮细胞进入分离通道；通过核酸酶对分离出的精子液的去游DNA处理，可得到单一、完整的精子分型。与传统的差异裂解法相比，这种方法在很大程度上节省了检验时间，在性侵案件中具有一定的法医物证分析价值。

microfluidic chip; sperm; epithelial cells; STR; separation

To develop the method for separation of sperm and epithelial cells in a microfluidic chip, the glass- PDMS chip, which is easy to manufacture, was selected to separation of sperm and epithelial cells. Buffer was added to the inlet （7 μL） and outlet reservoirs （10 μL） prior to sample addition, then a sperm/epithelial cell mixture （2μL） was added to the inlet reservoir. After a minimum of 8 rain of“settling time”, gravity-induced flow was initiated by removing 3 ~tL of buffer from the outlet reservoir, then the inlet reservoirs was supplemented with 1 ~tL buffer every 5rain. Follow- ing the desired separation time, product was removed from the outlet reservoir via pipet. Nuclease was used to remove free DNA, followed by extraction, amplification and electrophoretic separation/detection. By using microfabricated chip based gravity-induced flow mechanism, sperm can be separated from mixture in 30 min. No epithelial cells were observed passing through the channel during separation. After removing free DNA by using nuclease, a single and com-plete sperm STR profile can be obtained. Compared with the conventional differential extraction, this method can largely save test time and has a certain value for the analysis of forensic evidence in sexual assault cases.