Application of YO-PRO-1 as an epifluorescent dye for in situ detection of small amount DNA in plant cells

We examined organelle DNA, ie. plastid and mitochondrial DNA in the plant c ells such as the sperm cell of Jasminum nudiflorum, the generative cell of Pharbitis limbata, the cultured cell of Nicotiana tabacum and the root cell of Vicia faba with epifluorescence microscopy and laser confocal microscop y using YO-PRO-1 as a fluorescent dye. The excitation for YO-PRO-1 was blue light in epifluorescence microscopy and 488 nm Kr/Ar ion laser in confocal microscopy. Dimorphic epifluorescent spots that corresponded plastid DNA a nd mitochondrial DNA were distinctly detected in the cells of each species examined. In this report, we introduce YO-PRO-1 as a new epifluorescent dye for successful in situ detection of small amount DNA in plant live cells a nd cell sections with perticular emphasis on the importance of sample prepa ration.