Traditionally, this is done by gel electrophoresis--a process that uses an electric current to pull protein molecules through a substance called polyacrylamide.

• 从传统上讲，用凝胶电泳就可以做到。 凝胶电泳是用电流让蛋白质分子通过一种叫做聚丙烯酰胺的物质的过程。