Expression of protein X varies in different w.b running (in one cell line, but - (Nov/13/2011 )

Hi!

I do western blot regularly to check expression of protein X in 6 different cell lines. Now I've come across a problem with one cell line. When I run w.b. with this cell line's new cell lysate, I see different expression level (higher or lower) compared with my last result. I have no problem with the other 5 samples, but only this one.

What is the problem? Why this cell line's protein expression is not consistent with its last lysate?

p.s. I do not use any treatment. The origin of these cells are the same (colorectal). the passage and confluency is the same. the antibodies are the same, too.

Plz help me..................................

Are these normal or cancer cells?

EvilTwin on Tue Jan 3 11:08:09 2012 said:

Thanks for your reply. They aye all cancer cells.

I think it might be the cause. Cancer cell are genetically unstable and some of their features may change division-to-division.