multiple bands in western blot - (Jun/13/2006 )

Hi guys,

In a western blot with anti-gfp (1:5000) my with a gfp-tag expressed protein shows multiple bands which are about 20 kDa larger than expected. Does anybody know, why I get multiple bands and why there is no one in the right size. So I am not really sure if may protein is expressed in 293 T-cells or not.

Can anybody help?

if it's 2x or 3x the size expected it could be a dimer or trimer.

Thank you for your answer. Usually my protein should not build a dimer or trimer in vivo. Can it happen in spite of this that it builds a dimer or trimer in vitro?I have the same problem with a v5-his6-tag expressed protein. Do you know any other reasons for my problem?

greetings nora

Did you sequence the insert?
sometime you can insert twice, leading to a dimer.

Yes, I have sequenced the insert. I now heard that different degrees of glycosylation of the protein could cause the multiple bands.

Yes , this is also possible, and the size will change a lot.