I am looking for a good fixable probe for analyzing mitochondrial membrane potential in live human peripheral blood mononuclear cells. I have found that my options are:

a) MitoTracker Red CMXRos

b) MitoTracker Red CM-H2XRos (reduced, non-fluorescent version of the a)

c) Mitotracker orange CMTMRos

d) Mitotracker orange CM-H2TMRos (reduced, non-fluorescent version of the c)

I understand the difference of the reduced and not-reduced stains in principle but if I:

a) only expect a small variation in membrane potential

b) do not want to treat the cells with a mitochondrial toxin

Will it make any difference what stain I use? Do you have experience if one is more sensitive than the other?

Any input would be much appreciated!

Thank you in advance