> Hi everyone, > Does anyone know of a fluorescent probe which could be used > to assay > invertebrate cell viability and which can added with subsequent > fixation of the cells? The viability assay kits from Molecular > Probes all appear to be only useful for unfixed material. You could try mitotracker green or red from Molecular Probes : the dyes should only be taken up by live cells, especially those with a large number of mitochondria, and they are fixable. Check the catalogue - I'm pretty sure there are others too, which may be preferable for mitochondrially poor (?) cells. Ian. >< >< >< >< >< >< >< >< >< Dr Ian S. Harper Confocal Microscopy Facility Department of Biological Sciences Monash University, Clayton, Vic 3168 Australia ***Email: [log in to unmask] *** Tel: +61 3 9905 5635 *** Fax: +61 3 9905 5613 >< >< >< >< >< >< >< >< ><