Adhesion of tissue slice onto a glass substrate

[vini]

Hello,

I am doing an extracellular recording from a mouse retina. I use
planer metal electrodes on glass. However, the tissue when placed on
glass and perfused, starts to float in the medium, whatever small the
perfusion rate I keep. This is a big problem for me because for my
recordings, I need to have tissue sticking properly on the glass..

I have tried using a filter paper carrier, it still floats :(

Can someone help me in this regard?

Thanks,

Vini.

[Bill]

Hi Vini,

I have two thoughts. The classical way of holding down slices is to
bend a piece of platinum (1mm) into a U shape, and then adhere
(cynoacrylate glue) fine fibers across the U (so it looks like a
harp). Then use that to hold down you slice. I don't fully understand
the geometry of your electrode, but if the platinum causes a short
circuit, you can coat it in cynoacrylate, or by teflon coated wire. If
you're scared of compressing your retina, use a vice (with a flat
gripping face) and a micrometer, and compress the platinum down to the
nominal thickness of a retina, then put the harp on upside down, so
the fibres are only just touching the retina.

You can also try precoating the glass with something like laminin,
poly-L-lysine or a non-organic hydrophobic coating like sylguard. But
if you electrode is base of your chamber, this this won't really be an
option.

Your final option is to drop submersions recording, and use an
interface chamber.