ACAIN is a specific fluorescent dye to stain the tonoplast. It was developed in the lab of Csaba Mathe in Hungary, and we have got this dye, which is not commercially available, from them in 2018. The location is integrated into the chemical list. Stock solution should be 2 mg/ml in DMSO, which is diluted 100 x for use in living plant cells. It does not work well in fixed cells, in living tissues, roots were giving a diffuse signals, while in shoots, the signal was clear. The stock should be stored at 4°C.