mouse and rabbit antibodies in western blot - (May/25/2008 )

hello. i would like to know the size of the mouse and rabbit antibody. i found 50 and 25 for the heavy and light chains form my net browsing. is this correct? thanks.

I guess you mean IgG antibodies. There you have two light and two heavy chains which result together in a molecular weight of 150 kDa.
The other Igs may differ in weight because of a different glycosylation pattern and/or dimer (IgA)/pentamer (IgM) formation.
The different mammalian species shouldn't differ that much.