Comment by 5mk
I've always wondered about gel image fraud -- what's stopping fraudulent researchers from just running a dummy gel for each fake figure? If you just loaded some protein with a similar MW / migration / concentration as the one you're trying to spoof, the bands would look more or less indistinguishable. And because it's a real unique band (just with the wrong protein), you wouldn't be able to tell it's been faked using visual inspection.
Perhaps this is already happening, and we just don't know it... In this way I've always thought gel images were more susceptible to fraud vs. other commonly faked images (NMR / MS spectra etc, which are harder to spoof)
Gel electrophoresis data or Western/Southern/Northern blots are not hard to fake. Nobody seeing the images can tell what you put into each pocket of your gel. And for the blots nobody can tell which kind of antibody you used. It's still not totally effortless to fake as you have to find another protein with the right weight, this is not necessarily something you have just lying around.
I'd also suspect that fraud does not necessarily start at the beginning of the experiments, but might happen at a later stage when someone realizes their results didn't turn out as expected or wanted. At that point you already did the gels and it might be much more convenient to just do image manipulation.
Something like NMR data is certainly much more difficult to fake convincingly, especially if you'd have to provide the original raw datasets at publication (which unfortunately isn't really happening yet).