Is it normal to see 3 bands when looking at ERK1/2 (p42/p44) in a western using mouse brain?

I've begun examining ERK phosphorylation in vivo and previously my antibody for total ERK (Sigma M5670) gives me 2 bands (ERK1/2) in my HEK293 cell line, but now using it for mouse brain samples...

22 May 2015 4,481 2 View