Chu G, Vollrath D, Davis R W
Science. 1986 Dec 19;234(4783):1582-5. doi: 10.1126/science.3538420.
Electric fields can be manipulated by a method in which multiple electrodes are arranged along a closed contour and clamped to predetermined electric potentials. This method may be applied to a broad range of problems in the separation of macromolecules by gel electrophoresis. DNA molecules as large as 2 megabases can be well separated with a contour-clamped homogeneous electric field alternating between two orientations 120 degrees apart. The pattern of separation is independent of position in the gel, which is an advantage over previous methods. DNA less than 50 kilobases can be separated without distortion even at high voltage with a nonalternating contour-clamped homogeneous field. Decreased band broadening in DNA less than 200 bases can be achieved with a contour-clamped inhomogeneous field.
电场可以通过一种方法来操控，即沿着闭合轮廓排列多个电极并将其钳制在预定电势上。该方法可应用于凝胶电泳分离大分子的广泛问题中。长达2兆碱基的DNA分子可以在两个相隔120度的方向之间交替的轮廓钳制均匀电场中得到很好的分离。分离模式与凝胶中的位置无关，这是相对于先前方法的一个优势。即使在高电压下，小于50千碱基的DNA也可以在非交替的轮廓钳制均匀电场中无畸变地分离。对于小于200个碱基的DNA，使用轮廓钳制非均匀电场可以减少条带展宽。
