Labeling the endoplasmic reticulum with DiO-C6(3) for imaging

The eukaryotic cell has evolved to compartmentalize its functions and transport various metabolites among cellular compartments. Therefore, in cell biology, the study of organization and structure/function relationships are of great importance. The endoplasmic reticulum is a highly convoluted, single membrane that is continuous with the outer nuclear membrane and is believed to form a contiguous closed sac within the cell cytosol. Although a probe specific for the endoplasmic reticulum currently does not exist, the DiO-C(6)(3) probe, a cationic dye, is an effective label because of the distinctive intracellular morphology of the endoplasmic reticulum that distinguishes it from other intracellular organelles. This protocol describes the labeling of the endoplasmic reticulum with DiO-C(6)(3).