DiD is a lipophilic fluorescent probe. It is rapidly incorporated into phospholipid cell membranes and has been used to label the plasma membrane and endocytic organelles in bovine aorta endothelial cells and rat hippocampal slices. DiD has also been used to assess proliferation in prostate cancer cell lines by flow cytometry, where high DiD-expressing cell populations are associated with lower proliferation. DiD is not cytotoxic and can be detected in subcutaneously implanted PC3 cells in vivo after three weeks. It displays absorption/emission maxima of 650/670 nm, respectively.
