No protein on western blot but standard transferred - (Nov/03/2014 )

I'm using BioRad's kaledioscope protein standard, which transferred beautifully.  I became aware of this problem after staining for my gene of interest (which did not reveal a band) followed by tubulin staining with a known antibody that works well with westerns (also, no band).  So I dried the PVDF and added a few mLs of Invitrogen's SimplyBlue and let sit for 10 minutes, and there are no evident protein bands. 

The gel I ran my samples in was a precast 10% bis tris w/ MES buffer.  I did not trim any lanes before or after transfer, except for the top of the wells.  I did a protein quant via BCA, which gave me ~7ug/uL (turned purple almost instantly).  The lysate is not vicous, so I don't think it's clumping up at the top of the well.  The obvious next step is to just run the gel and do a coomassie on it, but what could possibly be the issue?

Have you tried diluting the samples to ensure that they aren't getting stuck at the top?

As the ladder is running, and transferring, the implication is that there is something going on with your samples that is either inhibiting the entry into the gel (most likely), or preventing transfer (possible, try adding some SDS to your transfer buffer).

Run a second gel and do a Coomassie stain.  If the problem is in the gel run, you won't see any bands in the stained gel, and if this is the case, you should probably try using MOPS as your running buffer, especially if your .  If you see bands, then the problem is in the transfer.  I've had this problem myself, and i noticed that for my wet transfers, the only thing that seems to be working is using a transfer buffer containing only 1X TG and 0.01% SDS (no methanol), then transferring overnight at 150-200 mA (make sure your power pack is set to constant current, not constant voltage.  Resistance will change in the buffer over the course of the transfer.  If I had a power pack that could do constant current, I wouldn't need to set 30 V overnight and pray the transfer doesn't get too hot) at 4 C.  And of course, if this doesn't work, I see that Bis-Tris gels can be transferred using NuPAGE transfer buffer

Of course, if you have a semi-dry blotter, then the issue may be with the electrode.  Check the cover for corrosion.  If it is corroded, you need to buy a new semi-dry blotter.