I am doing 2DE for a couple of years. I am working with the same kind of samples. Everything was good until now. I have the same problem each time. I repeated electrophoresis many times (other samples, but from the same, "good" part). Sudenly me gels stareded to look strange (I didn't change anything). As you can see on the picture my spots are "foggy" and in the albumin place I have a transparent gap (the picture is dark, because I added quite huge amount of formaldehyde to see what will happend). First I thought that this is samples fault. But I have new one and nothing gets better :(. I have already checked my reagents for silver staininig and there are ok. My water is also good (MQ water).

Please help me, I am waiting for some ideas.