Highly diffusible dye for filling neurons in vivo

Posted by Peter Rupprecht-2 on
URL: http://confocal-microscopy-list.275.s1.nabble.com/Highly-diffusible-dye-for-filling-neurons-in-vivo-tp7586162.html

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Dear dye experts,

I'm currently patching very small neurons (soma 5-10 um in diameter, dendrites much smaller) in living tissue. In addition to electrophysiological recordings, I'd like to get the morphology without fixing the tissue, so I add a dye (until recently mostly Alexa 594) to the pipette solution.

However, since the neuronal processes are very small, it is very often only the soma and not the small dendrites that get filled by the dye.

Switching from Alexa 594 to Alexa 488 improved things a bit (probably since 488 is smaller? https://en.wikipedia.org/wiki/Alexa_Fluor). But maybe somebody on the list has an idea of an even smaller, highly diffusible, non-toxic dye that I could use for this purpose. Plus, it should of course work with regular 2P excitation (800-950 nm).

Any ideas?

Best,

Peter