WNK3 was immunoprecipitated from 1 mg of HEK293 cell extract, 1 mg of rat testis extract and 1 mg of HEK293 transfected with Flag-WNK3 using 20 ug of anti-WNK3 antibody. The immunoprecipitates were subjected to SDS-Page and immunoblotted with anti-WNK3 at 2 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).