SDS PAGE smearing of bands

[exec]

 

Hello All,

 

We are facing a peculiar problem.

 

I have attached my SDS PAGE gel for reference. We get a pattern as if protein has spilled into adjacent well and the blank well (1st and last) also shows band. we have been performing the same method for same protein for about 7 yrs with no difficulty but from past 2-3 months are encountering this problem. we have tried preparing fresh reagents and do the test but same results. what can be the problem as while loading the protein does not spill, still this results is confusing.

 

Can anyone throw some light or elaborate on this. Any help will be appreciated.

 

Thanks in anticipation

 

[CharonY]

This is odd. Normally I would have assumed that there is something wrong with the pocket or during the loading step, but you say that it is not the case and it happens with each gel?

Does it only happen in the outermost lanes, i.e. have you tried running fewer lanes and see if it persists?

Also, what loading buffer do you use?

Edited June 24, 2011 by CharonY

[Essay]

...been performing the same method for same protein for about 7 yrs with no difficulty but from past 2-3 months are encountering this problem.

 

The same... for 7 years!

 

My first thought was that you have developed a very tough biofilm somewhere in your equipment (or water supply?), and that it is leaking some simple metabolite such as propionic acid, lactic acid, etc. But whatever, it sure looks like a contaminant from somewhere, eh?

~

[shaung]

are you running at the same voltage over the 7years? lower voltage may result in more passive diffusion across the lanes of the gel...