Fig. (2). SNARF ligand preferentially labels HaloTag-expressing HCT116 cells The HaloTag expression cells (HCT116-HT) and non-tag expressing parental cells (HCT116) were labeled with SNARF ligand prior to fluo-rescence microscopic imaging. Labeling by the SNARF ligand was observed homogenously in the HaloTag-expressing cells (merge). No red fluorescence was observed in the parental HCT116 cells. A corresponding bright-field image was acquired reveal morphology of cells. The width of the view is 150 µm.