western blot--prob - (Sep/21/2008 )

Hi
I am working on the western blots. I am unable to get exact size band (molecular weight) when compare with the marker. i have ab of 43 kda but my bands are showing at 60 kda???? howcome ??

could u please help whats the reason it could be?

Any possibility for post-translation modifications for the protein of interest?

could be non-specific bands. Do you have a negative or positive control to determine that what you are seeing is really your protein of interest?