Do FBM media work in polyacrylamide gels?
Most customers use 2% or 3% agarose gels instead of polyacrylamide because SB and LB resolve small fragments of DNA very well. This is nice since acrylamide pre-cast gels have a more limited shelf life than agarose gels and because agarose gels are easier to make. There is a feature of polyacrylamide gels about which investigators have long known to be careful. Ammonium persulfate (APS) is used to polymerize the acrylamide in order to create the polyacrylamide gel. APS is a salt, a high ionic load. Different investigators use differing amounts of APS to polymerize their gels, depending upon both the speed of polymerization desired and the age of the APS solution (it loses effectiveness even after one week, and so some investigators compensate by using more in their gels). To handle the ionic load of APS, for decades many investigators have preferred to “pre-run” their polyacrylamide gels so that the APS migrates out of the gel. They then load their samples and run the gel normally. If
