Immunohistochemical staining for SK3 and aquaporin-2 (AQP2) in WT mouse kidney sections.

<p>Top Panel (A–C): A low-magnification transverse section (5 µm) of the mouse kidney is shown. Discrete labeling is shown for staining for aquaporin-2 (<b>A.</b> AQP2, red), a marker of the collecting ducts, SK3 (<b>B.</b> SK3, green), and a merger of both channels (<b>C.</b> Merge, yellow-organge for co-localization of AQP2 and SK3). Labeling is apparent for SK3 in both the cortex (label C) and medullary (label M) (dashed line shows cortical-medullary demarcation). <b>Middle Pannel (D–F):</b> Magnified view of the yellow inset box from A. SK3 co-localizes with all AQP2-postive tubules as show by the yellow-orange images (F., asterisk). SK3 staining is also apparent in AQP2-negative structures including other tubular structures (F., arrows) and smaller secondary structures (possibly vascular structures, F., arrow heads). <b>Bottom Panel (G–H):</b> Magnified view of staining in the presence of SK3 blocking peptide. All SK3 staining is abolished demonstrating specificity of our anti-SK3 antibody. Scale bar is 50 µm.