Dimidium bromide

Dimidium bromide is a phenanthridinium compound with trypanocidal activity that affects nucleic acid synthesis in flagellate protozoa, bacteria, yeasts, and tissue culture cells; this molecule inhibits the growth of Amoeba proteus and Amoeba discoides, and the cellular response varies with drug concentration^[1].

Dimidium bromide can be synthesized via a trichlorotoluene-based process using 4,4'-dinitro-2-aminobiphenyl as the starting material.
Dimidium bromide (DimBr) (20 µM) colocalizes with both the nucleoplasmic marker H2B-sfGFP and the nucleolar marker Fibrillarin-sfGFP in N. benthamiana leaf epidermal cells, and can stain the nucleoplasm and nucleolus in living epidermal cells; it does not fully colocalize with the Cajal body marker Coilin-sfGFP, indicating that it does not stain all RNA-containing structures in the nucleus^[3].
Dimidium bromide (2 µM) exhibits strong fluorescence when mixed with DNA or RNA in vitro, with comparable fluorescence intensity for both nucleic acids^[3].
Dimidium bromide (20 µM; 10-20 min) can visualize nuclei in multiple cell types of N. benthamiana as well as in multiple plant species including Arabidopsis, lettuce, cucumber, and M. polymorpha^[1].
Dimidium bromide (20 µM; 10 min) can stain nucleoli and cytoplasm but not nucleoplasm in CHO-K1 cells, indicating that the staining characteristics of nucleoplasm and cytoplasm differ among biological species; moreover, it enables time-lapse imaging of nuclear migration in living Arabidopsis leaf epidermal cells in response to blue light irradiation^[1].