I have two questions. Thank you for having an interest in my question and please give me some advice.
I have a trouble for making patch pipette with thick wall capillary glass. I've have been used thin wall 1mm O.D. capillary glass, and it was easy to make appropriate shape and diameter with them.
To change the capillary glass from thin wall to thick wall, I struggled to adjust my pipette puller and finally I made a good example. But every time I make a new pipette with same setting the puller make quite different diameter of pipettes. It is not consistent. The pipette puller that I used was Narishige vertical type puller.
I tried to do same thing with Sutter horizontal puller, and I also found good setting values.. But it is also not consistent.
Does this just mean that I'm using wrong setting values and that I have to find more apt setting values?
Are there anyone who experience similar problem with thick wall capillary glass?
I'm doing slice whole cell patch clamp recording experiment with 2 or 3 weeks rat brain. It seems that getting whole cell configuration is not very difficult now, but I have a terrible problem with access resistance change during the whole cell configuration experiment. I think I usually throw almost 70% of results away due to the Ra change during the recording. My experiment is not even very long. The whole experiment protocol takes just 10 min.
I want to know whether this level of Ra problem is typical.
And, can changing pipette make it better? Are there anything that I can do to stabilize the Ra other than perforated patch?
Thanks a lot.