MitoSpy™ Orange and MitoSpy™ Red contain a chloromethyl group that covalently attaches to cysteines in the cell. This gives them a higher probability of remaining in a cell after the sample is fixed and permeabilized. However, as the fix/perm process washes out a large amount of the reagent, a much higher concentration of MitoSpy™ Orange and MitoSpy™ Red is required to get sufficient staining.
After the fix/perm process, most MitoSpy™ Green and MitoSpy™ NIR will be washed away. As such, they are not recommended to be used with samples that require fixation and permeabilization.
*Note that all MitoSpy™ products must be used on live samples. The recommendations below reflect whether MitoSpy™ is successfully retained following the "Retention Condition" treatment.