Dear Hu

it depends a lot for the origin of the smear, which may be different.

For example, in some cases, the presence of residual DNA can make difficult sample loading and induce some smear and in this case is the solution is the addiction of DNAse and not the change of gel and/or buffers.

Regarding the differences beetweek Tri-glicine and Bis-Tris you can find some information on a video on my blog: PRoteoCool (Overview on SDS-Page  at PAGE3)

ciao

Manuele

Hi, I agree with the answer above, in lot of case the problems is in the samples preparation and not in the gel. If you can upload a figure as example we can try to figure out the problem.

If you think that you prefer to change maybe this link can help you:

https://www.abcam.com/content/tris-glycine-vs-bis-tris-gel-chemistry

The Tris-Glycine gel formulation for gel electrophoresis is the simplest and most widely used system for separating a broad range of proteins using SDS PAGE or native PAGE (i.e., without SDS or alternative denaturant). Based on the Laemmli system it utilizes two Tris-Glycine gels; an initial stacking gel that focuses the proteins into a sharp band at the beginning of the electrophoretic run, followed by a resolving gel that separates the proteins based on their size. Tris-Glycine chemistry gels are known for their poor band resolution .

he conditions for electrophoresis (pH and buffers) are more favorable with Bis-Tris chemistry-based gels. These gels are HCI buffered and have a neutral operating pH. The running buffer can either be MES (50mM, with 50mM Tris) at pH 7.2 or MOPS (with Tris) at pH 7.7.

Compared to Tris-Glycine gels, these gels employ chloride as the leading ions and MES or MOPS as the trailing ions. With a sample buffer of pH 8.5, acidification of the polyacrylamide during running is reduced. Additionally, the neutral pH of the gel improves protein stability during running, resulting in sharper band resolution and accuracy.