Filling recording electrodes

Is there a preferred method of filling the recording electrodes with KCl? I'm using a 30 gauge needle, but I'm having trouble with bubbles.

Thanks.

I suggest that you place a droplet inside the capillary near the outlet first and turn the measuring head upside down so that the tip is filled by capillary forces. Then you can fill the glass capillary with a microloader tip mounted on a syringe. This should work fine in most cases. If you still observe bubbles, maybe it helps to tap against the measuring head with your finger tip.

We are also still optimizing the measuring heads/electrodes, so the filling should be even easier in the future.