Membrane localization of Als2cr4 transfected into HEK293 cells. Confocal microscopy images of 6xHis tagged-Als2cr4, transiently transfected into HEK293 cells. Als2cr4 subcellular localization was identified by immunohistochemical labeling with antibodies recognizing Als2cr4 with pAb FLJ-FM (green; a, b) or the His-tag with mAb 6xHis (red; c, d). Nucleic acids in the nuclei were labeled with TO-PRO 3 iodide. Cells transfected with a recombinant Als2cr4 cDNA construct expressed the recombinant Als2cr4 protein, which is localized to the cytoplasm and the plasma membrane, (f) whereas those transfected with no recombinant cDNA inserted into the pCDNA4/HisMax vector (e) exhibited no Als2cr4 expression, and the His-tag was limited to the nucleus. Labeling patterns of Als2cr4 pAb (b) and 6xHis mAb (d) displayed co-localization in the plasma membrane (f), thereby confirming Al2cr4 antibody specificity.