| | Re: Control protein is nice, but target protein is blur and not sharp
Most likely there is some degradation going on. Each protein has its own properties. Some are very stable while other are highly unstable.
Take as many precautions as you like to maintain your protein, like : avoid freeze-thawing cycles, use proteinase inhibitors, EDTA, buffer up to pH 8 (pH drops with temperature in most buffers), DTT.
I usually get nice bands on the Western despite what the gel band looks like; best strategy is not to load too much protein on gel, and have optimized Antibody concentrations/dilutions for the WB.