Desruisseaux C, Slater G W, Drouin G
Department of Biology, University of Ottawa, Ontario, Canada.
Electrophoresis. 1998 May;19(5):627-34. doi: 10.1002/elps.1150190503.
It has previously been shown that zones of higher electric field form close to the loading end of the gel during denaturing polyacrylamide gel electrophoresis. Here we show that the field can reach up to three times its normal mean value a few cm in front of the loading wells when 44.5 mM Tris-44.5 mM boric acid-1 mM EDTA is used as the gel buffer. We also demonstrate that this electric field gradient is mostly due to the difference in ion transference numbers at the gel/buffer interface caused by the high viscosity of the urea solution contained in the gel. This field gradient leads to increased band widths and forces us to redefine both the electrophoretic mobility and the mean field intensity. We discuss some methods that can be used to minimize the effects of this gradient.
先前已经表明，在变性聚丙烯酰胺凝胶电泳过程中，较高电场区域会在凝胶的加样端附近形成。在此我们表明，当使用44.5 mM Tris - 44.5 mM硼酸 - 1 mM EDTA作为凝胶缓冲液时，电场在加样孔前方几厘米处可达到其正常平均值的三倍。我们还证明，这种电场梯度主要是由于凝胶中所含尿素溶液的高粘度导致凝胶/缓冲液界面处离子迁移数的差异。这种电场梯度会导致条带变宽，并迫使我们重新定义电泳迁移率和平均场强。我们讨论了一些可用于最小化这种梯度影响的方法。
