Viability

A couple of (perhaps) naïve questions:

7aad seems to have been around for ages and appears to give good separation
of cells that are (apparently) live and dead. Yet, there seems a clear trend
away from an old fashioned dye like 7aad to other products (eg the range of
Mol Probes viability/vitality dyes). Is there something I'm missing about
7aad not doing the job? If the others are better than 7aad, can someone tell
me why. Is it just the colours they are detected in, or something more than
that? I want to use the best approach and happy to change from 7aad if need
be, but don't want to change for change sake.
Any advice?

On a similar topic, we stain human PBMCs with 7aad in the antibody staining
cocktail, then wash, then fix then run the samples. This gives us good
separation of positive and negative peaks, which we take to indicate cells
that were alive versus dead prior to fixation. Are we wrong to do this? I
see lots of instances where people say things like 7aad or PI can't be used
for fixed cells. Our approach seems too obvious for people to have missed,
hence I'm wondering if there's something wrong with doing it that way.
Anyone have any comments?

Regards,

Stuart


Dr Stuart Berzins
NHMRC RD Wright Fellow
Department of Microbiology and Immunology,
The University of Melbourne,
Parkville 3010,
AUSTRALIA.
email: berzins@unimelb.edu.au
Ph (office): +61-3-8344-5706
Ph (lab): +61-3-8344-5704
Fax: +61-3-9347-1540
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