SDS-PAGE Contaminant Bands Question

Hi, I was wondering if anyone had suggestions as to what may be causing contaminant bands in an SDS-PAGE method I'm running.  I'm using LDS buffer, MES running buffer, and 4-12% Bis-Tris gels from Life Technologies.  I ran three different gels using the same sample buffer but the contamination showed up in only one of the gels.  The buffer blank lanes are loaded with mixture of 4X LDS, reducing agent, and water.  I've attached an image of the gel.  I suspect it may be the running buffer.  Any thoughts are appreciated.

Thanks,

Brandon

 HI can u label the gel?

are you refering to the thick bands in 3 lanes or the faint band in intermediate lanes? If latter is the case then it is because of buffer overflow from 1 chamber to another

Hi Argerine, I've attached another image with the contaminant bands labeled.  How is it that buffer overflow from one chamber to another causes such bands?  Again, the same running buffer was used for three different gels and only one showed these bands.  I seem to only have this problem when running this particular SDS-PAGE method.  Thanks for your help.

-Brandon

The altered image wouldn't attach.  I am referring to the light streaky bands you see in the intermediate lanes as you mentioned before.  They don't appear to be related to carryover from adjacent lanes.

Thanks,

Brandon

 Hi Beeman

That is a problem of protein carryover from adjacent lanes. When u added buffer to your gel some of the protein from sample buffer got displaced to the adjacent well. This is based upon the same position of bands in the lanes.