Mouse kidney lysates (30 ug) were resolved on an 8 % SDS-Page gel and transferred to nitrocellulose membrane. The membrane was probed with anti-SPAK (2 – 76) S668D with the indicated bleeds at 1 ug/ml.

HEK293 cells were transfected with constructs encoding full length mouse FLAG-tagged SPAK wildtype, FLAG-tagged SPAK L502A and full length mouse FLAG-tagged OSR1 wildtype. 36 hours post transfection, the lysates were subjected to immunoblotting with the indicated antibodies. The results indicate that anti-SPAK (2-76) S668D antibody is specific for mouse SPAK and does not cross-react with mouse OSR1.