so this is DNA that you've cut up into fragments

例如有一段你用限制酶
using restriction enzymes for example.

切割成片段的DNA
You load them into the top of a gel and a gel is -

你把它安置在一段凝胶上凝胶是--
in this case it's synthetic polymer gel but it looks very much like Jell-O.

这种合成凝胶聚合物看上去很像吉露果冻
I'm sure some of you have dealt with electrophoresis gels in the past and

我相信在座肯定有些已经接触过电泳凝胶
it's really just a slab of something like Jell-O

真的挺像一块板状果冻的
where you can put a sample at one end of the Jell-O,

你可以把一段样本放在"果冻"的一端
your sample of fragmented DNA.

你的DNA片段样本
Now you apply electrical charge across that Jell-O.

然后在"果冻"两边加上电压
Because it's a gel electricity is going to move through the gel

由于凝胶中存在离子
because there are ions in it the same way -

电流会通过凝胶同样--
for the same reason you don't drop an electrical device into the bathtub

因为同样的原因你不会把电器扔进浴缸里