Its certainly been done with SR101. For instance see Appaix et al (2012) PloSone, volume 7, issue 4, e35169. And alsewhere, but thats the reprint on my desk ... The title by the way is "Specific in vivo staining of astrocytes in the whole brain after intravenous injection of sulforhodamine dyes". So what are YOU wishing to do?

yea, i found that one as well..i wanted to try to stain astrocytes in insect cns and that sounds like an efficient method (if sr101 works in insects, which is not proven yet..). My main concern was for the membrane dye RH795, which is used to enhance the contrast when imaging with 2-photon microscopy and I am not sure how it would diffuse well into the brain if injected systemically..

Neat idea. Let me think about it ... by the way, my interest in such reagents is that I want to take a chemical structure and use that to predict [via QSAR models] where such a compound would get to in a living cell, google scholar finds a lot of modeling stuff under my name if you were curious ... OK. RH 795 is not a dye I have any direct knowledge of. So its used for neural functional imaging, I presume to measure membrane potential? What do you mean when you say the RH dye should enhance the contrast? Re diffusing well ... it is predicted [this is QSAR model stuff] to have a weakly amphiphilic character, so yes it sticks into membranes. But this wouldnt be selective for neurones or glia ... EVERYTHING ... so if you put it in by iv most would predumably get trapped on the plasma membranes of the endothelial lining of the blood vessels, and indeed the plasma membrane of the blood cells. Hohum?

you are correct..it is a dye that sticks to any membrane and for this reason it is used to visualize structures in the brain with 2-photon microscopy (membrane are more dense where a structure terminates, therefore the dye will enhance the border of a strcuture such as the olfactory glomeruli, for example). For this reason, as you say, it may stick to anything it finds if I inject it into the blood...however, the blood reaches all compartment, so it may also diffuse evenly and stain evenly all strctures in the brain. And this is what I was wondering....