At 01:55 PM 04/11/2000 +0200, you wrote:
>Dear all,
>We´re looking for a dye to measure membrane potential in smooth
>muscle cells (gallbladder), using a confocal micro (though we could
>also use a conventional CCD camera). We don´t know which kind
>of dye (slow, fast) we should use. If any of you have any
>experience, please let us know.
>
>Dr Pedro J Camello
>Dept Physiology
>Fac Veterinary Sci
>Univ of Extremadura
>Campus Universitario
>10071 Caceres
>SPAIN
>Phone/Fax: 927-25-71-54
>[log in to unmask]
 
JPW114 is a pretty good potential sensitive dye. It has an excitation
wavelength of 510 nm and a red emmission (around 640 nm). It is a fast
potential sensitive dye. We used it to measure action potentials in
isolated cardiomyocytes (Jaconi et al. Mol Biol. Cell 11, May 2000). Antic
and Zecevic used it to measure membrane potentials in neurons. You will
find characteristics and properties of this probe in their original
publication (J Neurosci. 15, 1392-1405, 1995, also in Zecevic Nature 1996
23;381(6580):322-5).
good luck
michel
Michel Puceat, Ph.D
Centre de Recherches de Biochimie Macromoleculaire
CNRS UPR 1086
1919 Route de Mende
34293 MONTPELLIER, Cedex 5, France
Phone  lab:(33) (0)4-67-61-33-50 or 33-54 
Fax: (33) (0) 4-67-52-15-59 
http://www.crbm.cnrs-mop.fr/homegb.html
ftp://ftp.crbm.cnrs-mop.fr/users/gtpases/puceat