02406nas a2200217   4500008004100000022001400041245010000055210006900155260011000224300001400334490000600348520158500354100001601939700001501955700001901970700001801989700001602007700002502023700001702048856012302065       2015                        eng d  a2050-750X00aNew imaging reagents for lipid dense regions in live cells and the nucleus in fixed MCF-7 cells0 aNew imaging reagents for lipid dense regions in live cells and t  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcAUG  a7177-71850 v33 a<p>Two new uracil (U) and 5-flurouracil (5-FU) labeled ruthenium(II)-polypyridyl based cellular imaging reagents are reported. Confocal laser scanning microscopic images with live and paraformaldehyde (PFA) fixed MCF-7 cells are examined using these two low-cytotoxic reagents. Experimental results show that these two complexes, appropriately functionalized with U (1) and 5-FU (2), have specific affinity for the lipid dense regions like the endoplasmic reticulum, cell membrane, and cytoplasmic vacuoles in live MCF-7 cells, and dye internalization in these regions happened following an endocytosis pathway. Interestingly, these two complexes are found to be localized in the nucleus of the PFA fixed cells. For fixed cells, presumably the lipid layer disruption helped in the explicit localization of the complexes 1 and 2 in the cell nucleus through specific interaction with cellular DNA. Poor and non-specific internalization of an analogous model complex 3, without having a U or 5-FU moiety, reveals the definite influence of U or 5-FU as well as the role of lipophilicity of the respective complex 1 and 2 in the cellular internalization process. Apart from these, a large Stokes shift (similar to 160 nm) and an appreciably long lived (MLCT)-M-3 excited state (similar to 320 ns) in aq. buffer medium (pH 7.4) are other key features for complexes 1 and 2. Unlike the common nuclear DNA staining reagents like DAPI, these low-cytotoxic reagents are found to be highly stable towards photo-bleaching upon irradiation with 455 nm at the MLCT band for these complexes.</p>1 aRamu, Vadde1 aAli, Firoj1 aTaye, Nandaraj1 aGarai, Bikash1 aAlam, Aftab1 aChattopadhyay, Samit1 aDas, Amitava  uhttps://library.ncl.res.in/content/new-imaging-reagents-lipid-dense-regions-live-cells-and-nucleus-fixed-mcf-7-cells-0