Antibodies for different epitope giving bands of different sizes in the same sam - (Nov/11/2007 )

Hi,

I'm been trying to detect a Protein, using 2 sc antibodies, one recognize N-term, the other the C-term. I've bands of 2 different sizes with these Abs using the same samples (50kD and ~62kD)! In addition, transfected cells for the protein shows yet another size (~55kD) (but in this case, both Abs give the same size.). Can anyone offer any explanation?

Thanks!

This could be an explanation.

Probably, the antibodies are detecting a different variant of the same protein. And when you transfect the cells, you are using only a single variant transgene, so the antibodies detect only 1 of them.