actin MW problem in western blot - (May/18/2009 )

hey all,

i am doing western blots and for my loading control (actin), i am consistently getting a specific band at 55-60 kd (the expected size is 42 kd). these are 293 cells that have been infected with adenovirus containing a gene of interest. im having trouble explaining why my size is off. any thoughts?

my actin also comes down to 50-60KDa...I bought from Sigma.

Curtis on May 19 2009, 02:20 AM said:

interesting. mine is from sigma as well (monoclonal actin). any explanation as to what it is running higher? bound to another protein? post-translational modifications? what cell line are you using.

We use Abcam A16 actin, it runs at about 46 kDa and is very strong. The ab we had from before (either sigma or santa cruz?) was a goat and very dirty with quite a few non-specific bands.

This is good to know!