I am going to study histochemical localization of Cd for the roots and leaves using a staining -based method with dithizone. Because of time limitations, I am not able to use the fresh samples immediately after harvesting. So 1- I need a proper fixator to keep the plant samples for a period of time. Please tell me the exact composition of the fixator.

2-Does anyone know how is the dithizone reagent prepared to detect Cd histochemical localization? and what is the its solvent?

Thanks in advance for your reply