USP9X or USP9Y was immunoprecipitated from 1 mg of mouse testis extract using 5 ug of anti-USP9X [S534B] or anti-USP9Y (2491-2512) [S363C] antibody. 20 ug of mouse testis and brain (male and female) extracts, along with the immunoprecipitates were subjected to SDS-Page, transferred to nitrocellulose and immunoblotted with either anti- USP9X [S534B] or anti-USP9Y (2491-2512) [S363C] at 1 ug/ml. Binding of the primary antibody was detected using rabbit peroxidase conjugated anti- sheep IgG antibody (1 in 10, 000 dilution, Pierce) followed by enhanced chemiluminescence (ECL, Amersham).