Hai,
I have i problem with my SDS PAGE result. At the bottom of the band, the line is shrink (pipete like form). My sample is protein extract from shark cartilage. I use 12%T, 6%C (resolving gel) 5%T, 3%C (stacking gel) and tris-glycin for running buffer. Do you know what causing that my band is shrink at the bottom? is that because of high calcium content in my sample? what kind of sample preparation to solve the problem? thanx

can you show us the gel photo?

How long do you rrun your gel? It sounds like the gel problem instead of the sample problem to me.

sounds like a salt problem (ca that you mention and maybe others). what buffer is your sample in before you add loading buffer? do you dilute?

I had this happen to me last week. At the time I thought that it had something to do with the temperature of the gel - gel was too cold while samples were too hot (I had boiled them) when I loaded them. It only happened once though. Does this always happen to your gels?