[Protein-analysis] 7kDa protein electrophoresis

[Daniel Kerr]

I'm trying to detect a 7kDa protein by Western Blot.

I've ran the cell lysate in a 15% acrylamide gel and the problem is,
proteins bellow 14kDa just vanish.

The Molecular standard is broad range (6-150kDa) and even the weight
doesn't show in coomassie or in the ponceau (I've stained half the gel
and transfered the other half).

Does anyone has a tip or similar problem?

Thanks