Malachite green acts as a respiratory poison, damaging the cell’s ability produce energy to drive vital metabolic processes. Formalin is a powerful disinfectant used to kill microorganisms or as a preservative for biological specimens. It works by reacting with cell proteins and nucleic acids - altering both structure and function. These chemicals can be used separately but are usually used together because they exert a synergistic effect; that is, together they give a greater effect than the sum of their separate individual capabilities.