I want to stain a phytoplasma in the phloem of infected plant samples previously fixed in FAA, washed in distilled water and cut freehand. In general, all DAPI techniques rinse with a buffer solution after staining. It seems to me that it would be unnecessary since both the sample and the stain are in distilled water. Does anyone have experience on this issue?

Also I did not find references in which the material fixed in FAA is used to stain with DAPI (generally glutaraldehyde is mentioned as a fixing medium and buffers to rinse)