Dear all. I am facing difficulties with staining of fixed plant tissue in diverse herbaceous species. In some species (about 10% of the studied species), I see nonspecific staining of cell walls and chloroplasts, without mostly any signal in cell nuclei. I am using fixed (Clark solution (ethanol+acetic acid) plant tissue (leaves,or stems), hand made cross-sections, washing in PBS, DAPI v PBS staining for 15 min and DirectRed for 15min for cell wall staining, confocal microscopy. I know that chloroplasts might be stained a bit because they also contein DNA and lignin has some autofluorescence under UV. But in this case, the samples are not lignified so much to be stained everywhere. I would appreciate any siúggestions for the protocol improvement. Thank you, Ren.