 |
 |
 |
 |
 |
>Out of interest, what is here the 'gold standard'? We in Aber are
>beginning to have suspicions that supposedly pure(ish) TO-PRO[3],
>or likely a metabolite / degradation product thereof, penetrates (and
>ergo stains) ""live"" [i.e. not all that knackered] cells (bugs).
>
The permeability characteristics of bacteria definitely vary over a greater
range than do those of the animal (mostly mammalian) cells commonly studies
by flow cytometry. A lot of people have used ethidium as a live-dead stain
for mammalian cells, but it does get into live cells, especially at alkaline
pH, whereas propidium is much less likely to do so and should therefore be
preferred. Ethidium gets into many live bacteria. Propidium and, more
recently, the "impermeant" cyanine nucleic acid stains, e.g., YOYO- and
TOTO-1 and 3, TO-PRO-3, etc., have been considered 'gold standards' for
animal cells, but should not necessarily be thought of in the same way for
prokaryotes, plants, and perhaps some animal cell types.
-Howard
|
|
|
|
|
|
CD-ROM Vol 3 was produced by Monica M. Shively and other staff at the
Purdue University Cytometry Laboratories and distributed free of charge
as an educational service to the cytometry community.
If you have any comments please direct them to
Dr. J. Paul Robinson, Professor & Director,
PUCL, Purdue University, West Lafayette, IN 47907.
Phone: (765)-494-0757;
FAX(765) 494-0517;
Web