In view of the problem of rhodamine 123 fuorescence bleeding into the PE
channel there are two possible solutions.
Either one uses MitoTracker Green FM (Catalog # 7514), which has a much
narrower (green) emission than does rhodamine 123.
Or one uses MitoTracker Red CMXRos (Catalog # M-7512), which has its
excitation maximum at 594 nm, but receives reasonable excitation at 488 nm.
Its emission maximum is at 608 nm, but some 10 % of maximum emission is seen
at 590 nm. If you excite at 488 nm (with say 100 mW) that 590 nm emission
is low enough that you can eliminate it from the PE channel with a bit of
electronic compensation. Thus, the MitoTracker Red CMXRos dye is compatible
with an FITC and an PE labeled antibody used simultaneously.
Both MitoTracker Green and MitoTracker Red are retained after cell fixation
with formaldehyde (data to be published in the October or November issue of
the Journal of Histochemistry and Cytochemistry).
Both dyes are available from Molecular Probes, Inc., P.O. Box 22010, Eugene,
OR 97402, U.S.A., TEL: +1-541-465-8300; FAX +1-541-344-6504:
or from Molecular Probes Europe BV, Rijnsburgerweg 10, 2333 AA Leiden,
TEL: +31-71-5233-431: FAX: +31-71-5233-419.
Hope this may help you,
Martin Poot