In pollen tubes, SNARF-AM is taken by vacuole/endomembrane system in a matter of less than 5 min. I tend to think that most AM probes will behave likewise, and this is specially evident when you use 2P which produces better optical sectioning than confocal. I tend to think that results better than this are based on less stringent optical sectioning which fails to reveal all the small vesicles loaded, thus misleading observers that interpret the signal as cytosolic (as we were doing before...). The BIG vacuole may in fact take a bit more time to observe the acumulation of the dyes (less than hour, though).
I don't think there is much alternative to DEXTRAN-linked dyes for active growing plant cells.
My two cents.
Jose

*********** REPLY SEPARATOR  ***********

On 08-12-2000 at 13:35 Subbaiah C. Chalivendra wrote:

>I haven't tried these dyes but worked with esters of fluo-3, rhod-2
>and snarf-1 to a small extent in maize cells. I used low
>concentrations of the dyes and checked the loading periodically. I
>used cultured maize cells and the problem with this cell line was not
>so much of cell wall esterases but the compartmentalization of the
>dyes.
>
>Subbaiah, C. C., D. S. Bush and M. M. Sachs. 1998. Mitochondrial
>contribution to anoxic Ca2+ signal in maize cells.  Plant Physiol.
>118: 759-771: www.plantphysiol.org/cgi/content/full/118/3/759).
>
>Subbaiah, C. C., Bush, D. S. and Sachs, M. M. 1994. Elevation of
>cytosolic calcium precedes anoxic gene expression in maize
>suspension-cultured cells. Plant Cell  6: 1747-1762.
>
>Subbaiah
>--
>Subbaiah Chalivendra, Ph. D.
>S-27 Turner Hall
>Dept. Crop Sciences, 1102 S. Goodwin Ave
>University of Illinois
>Urbana, IL 61801-4730
>
>Phone: 217 333-9743
>
>Fax:   217 333-6064