Western blot analysis of the rat IAP proteins distribution in adult rat tissues. The protein samples prepared from fresh adult rat tissues, or bacterially expressed GST-fusion recombinant proteins, were separated on 10% SDS-PAGE (12 μg total protein per lane) and transferred onto a PVDF membrane using standard techniques . Rabbit polyclonal antibodies against rat iap-1 (top), iap-2 (middle), and iap-3 (bottom) were used at 1:1,000 dilution followed by secondary antibody (horseradish peroxidase-conjugated goat anti-rabbit IgG; Amersham) used at 1:1,500 dilution. Antibody complexes were detected using the ECL system (Amersham). Position and size of the markers is indicated on the left. (Note that the recombinant GST-fusion proteins are larger due to the presence of N-terminal GST tag.) Tissues used are as follows: (1) brain, (2) heart, (3) intestine, (4) kidney, (5) liver, (6) lung, (7) spleen, (8) testis, and (9) thymus.