Li Xiang, Luo Long, Crooks Richard M
Department of Chemistry, The University of Texas at Austin, 105 E. 24th St., Stop A5300, Austin, TX 78712-1224, USA.
Lab Chip. 2015 Oct 21;15(20):4090-8. doi: 10.1039/c5lc00875a. Epub 2015 Sep 4.
We present a new paper-based isotachophoresis (ITP) device design for focusing DNA samples having lengths ranging from 23 to at least 1517 bp. DNA is concentrated by more than two orders of magnitude within 4 min. The key component of this device is a 2 mm-long, 2 mm-wide circular paper channel formed by concertina folding a paper strip and aligning the circular paper zones on each layer. Due to the short channel length, a high electric field of ~16 kV m(-1) is easily generated in the paper channel using two 9 V batteries. The multilayer architecture also enables convenient reclamation and analysis of the sample after ITP focusing by simply opening the origami paper and cutting out the desired layers. We profiled the electric field in the origami paper channel during ITP experiments using a nonfocusing fluorescent tracer. The result showed that focusing relied on formation and subsequent movement of a sharp electric field boundary between the leading and trailing electrolyte.
我们展示了一种新型的基于纸张的等速电泳（ITP）装置设计，用于聚焦长度范围从23至至少1517 bp的DNA样本。DNA在4分钟内被浓缩超过两个数量级。该装置的关键组件是一个2毫米长、2毫米宽的圆形纸通道，它通过对纸条进行手风琴式折叠并对齐每层上的圆形纸区域而形成。由于通道长度较短，使用两个9 V电池可轻松在纸通道中产生约16 kV m(-1)的高电场。这种多层结构还使得在ITP聚焦后，只需打开折纸并剪下所需层，就能方便地回收和分析样本。我们在ITP实验期间使用非聚焦荧光示踪剂描绘了折纸纸通道中的电场。结果表明，聚焦依赖于前导电解质和尾随电解质之间尖锐电场边界的形成及随后的移动。
