The NaK ATPase is an active transport protein that exports 3 Na ions and imports 2 K ions across the basolaterla membrane at the cost of 1 ATP molecule. This process maintains the high extracellular-to-intracellular Na gradient that provides the driving force for Na-coupled nutrient and ion transport across the apical membrane.  

Antibody validation
This commercial mouse antibody from Abcam (ab7671) is a monoclonal antibody raised against the native, full-length rabbit alpha 1 sodium potassium ATPase subunit. Our validation included staining of formalin-fixed, paraffin-embedded human duodenum, where the antibody labeled lateral membranes and colocalized with E-cadherin.