Subcellular localization of HA-tagged ABCA1 in HEK293H cells. HEK293H cells expressing the wild type (HA-WT) or double mutant variant (HA-MM) of HA-ABCA1 were immunostained with anti-HA antibody and visualized by confocal microscopy (green). As a negative control HEK293H cells transduced with the empty vector was used. Various cellular markers (wheat germ agglutinin, anti-Giantin and anti-EEA1 antibodies, as well as LysoTracker) were used to identify the different cell organelles (red), whereas DAPI staining was used to label the nuclei (blue). Both wild type and MM variant of HA-ABCA1 were localized predominantly in the plasma membrane. The minor intracellular staining colocalized primarily with the Golgi marker, and rarely with the endosomes (see white arrows). The scale bars indicate 10 μm.