When trying to do whole-cell recording in dissociated cortical neurons, I am very often not able to get a gigaseal, because before the seal is formed, I somehow snag the nucleus. I read that this is called a "nucelated patch". But I do not want it, and I have no idea what I can change to avoid this.
I approach the cell without pressure and after an approx. 30-50% increase of the resistance (pipette has around 5 MOhm), I apply some suction to increase the seal. On the other hand, sometimes I am able to open the cell, but I can not tell what the difference in my approach was.
Anybody else has this problems, or does anyone know what goes wrong here?