DiYO™-1 [equivalent to YOYO®-1] *5 mM DMSO Solution*

DiYO™-1 is chemically equivalent to YOYO®-1 (YOYO® is the trademark of Invitrogen). DiYO™-1 is a carbocyanine dimer with green fluorescence similar to FITC. It is cell-impermeant and easily distinguished from Cy5 and rhodamines as a nuclear counterstain and dead cell indicator. It is non-fluorescent in the absence of nucleic acids, and generates a very bright fluorescence signal upon binding to DNA. DiYO™-1 gives strong and selective nuclear staining in cultured cells and in paraffin sections. Simultaneous labeling with cell-permeable Nuclear Red™ LCS1 dye and cell-impermeant DiYO®-1 can be used to assess cell viability. DiYO™-1 and Nuclear Red™ both have much greater extinction coefficients than that of DNA-bound propidium iodide.